Just because you have people who know how to develop a laptop doesn't mean those same people know how to develop a games console, c'mon. Besides it is about much more than just the hardware; API libraries are also important and those are often tailored to specific hardware implementations as well. Also it's rather foolish to think they should prioritize what engineers they get based on what the console has sold in the market; a console's sales are in no way dominantly dictated by how well-engineered or powerful it is. Otherwise many older systems would've been not only market leaders but been leaders in every single territory their system was in. That is very clearly not the case when looking at actual prior console generations.
Considering their experience with large-scale API libraries having cross-platform support between embedded systems (like Xbox consoles) PCs, and servers, and considering Apple are in those same segments while also desiring to leverage existing APIs and features tailored to an embedded systems design, it actually makes a lot of sense they'd want various Microsoft engineers to provide their talents in such an area.
In terms of hardware an iPad Mini is basically a Switch with other brand for the APU, and an Xbox basically a PC plugged to a tv. And in fact the hardware from smartphones, tablets, handheld consoles, home consoles and PC is becoming essentially the same, unlike many years ago they now share a lot of stuff. Obviously each device is different but compared to many years ago now they are way more similar.
Also please notice that the ones they are poaching are the Xbox ones, not the DirectX ones. Microsoft's gamig API is DirectX, being used on Xbox and Windows (not in phones or servers). Regarding crossplatform APIs Apple also has big experience sharing their stuff between their Apple iOS, MacOS, watchOS and tvOS devices. They are pretty much integated into an unified ecosystem where UI, controls or the enabled features are adapted to each OS but most of the other things are the same.
That's not how it works; you're vastly oversimplifying the work that goes into creating a dedicated gaming system, as in something which vertically integrates hardware specifications, software specifications (API libraries, general code libraries, documentation, debug testing etc.) and more, into a static design whose specifications are set in stone for the next several years.
I'm a game programmer who made games for PC and mobile even before Steam, Unreal Engine (well, on its current super multiplatform 'free' form), Unity, iOS/App Store or Android/Google Play existed and the hardware not only between mobile and PC, but even between different phones was huge and it was a pain in the ass to do everything by ourselves.
Now things are way simpler because the harware is more similar everywhere, platform/store specifications standarized way more than before. It's still a pain in the ass to fill all these huge checklists specially in console, but in the past for phones & tablets now we have the Apple App Store and the Google Play ones, while in the past we had many for each phone brand manufacturer (some of our games were installed/bundled in the phone once you bought them) and many for the phone ISPs that sometimes even did have different ones for each country (before having Apple App Store or Google Play, the digital games for phones were bought at digital stores of the phone manufacturers or your local phone ISP).
Now there are also way less OS, APIs and game engines, and are way better once because they already implement a ton of work we the gamedevs had to do in the past. Regarding APIs guess what, Direct X is for PC and Xbox and has pros and cons, being a huge con that it isn't available on the other consoles, PC operative systems like Linux or MacOS or in phones. So this is why the crossplatform OpenGL, Vulkan and so on got so popular on multiplatform projects. These new OS, APIs and engines do a great job covering tons of devices partly because the hardware became so similar to a point where many game devs mostly don't care while in the past we had to carefully plan everything to put a game in phones that didn't accept games bigger than 128KB, 64KB or even 30KB (vs now we saw GT7 being 110GB, nice optimization! xD).
By your notion Sony could just take one of their random smartphones, pair it with a DualSense and viola! They have a new PlayStation Portable! Clearly wouldn't be the case now, would it?
In the Apple Store they sell DualSense gamepads to play PS Now and Remote Play on your iPhone or iPad. You can also use them on Android. In the past Sony made the Xperia Play, a phone that had games compatible with their portables.
If desired yes, they could release some of their games on phones similar to what games like Fortnite do. They don't do it because their focus is console and want to save giving 30% of the revenue to Apple or Google (see the case of Epic) because they have the monopoly of selling games on their platforms. But the userbase of mobile became way huger than console to the point where they are working to bring their IPs to mobile, even if I assume that will be making games designed to the horsepower and controls of mobile devices instead of porting directly their console games.
That's only one side of the equation. You know as well as I that a "proper" console also needs to have features and content specific to its ecosystem in order to incentivize clients into that ecosystem and keep them there, which means major development investments from the platform holders.
Apple already has a gazillion players, and a ton of devs including most of the popular console ones already working for their devices (and not only the announced ones

).
Remember that Apple makes more revenue from gaming than MS (with the ABK acquisition MS will pass Apple) or Nintendo even if they don't publish games and without having a console. Simply by collecting the 30% of what their game store, game microtransactions on their OS and game subscription generates.
Ensuring Unity/UE support their APUs and OS (BTW what incentives could Apple provide to ensure this for those engine owners beyond what they already provide?) would be the bare minimum thing for Apple to do.
True, this is why they partner with them to get their new stuff supported day one (or asap, in a few cases new stuff wasn't supported day one).
This still does very little in and of itself, because either Apple would then need to retroactively add support for that controller to ALL of the games currently on their Apple Arcade platform, or they'd need to convince 3rd-party developers to do it themselves.
Either way, it would be a large undertaking and involve a lot of resources (and time) either way, they can't just simply release the controller and magically everything works with it.
Both on iOS and Android there's a standard unified controller support which supports tons of 3rd party controllers. Hundreds or thousands of native mobile games already support them. Or you can use these pads to play Remote Play, Game Pass Ultimate or (soon) PS Now and so on.
They can make a new controller that uses that same standard controller support (so instantly would be supported by them), or simply adopt one of the many already supported ones. Then they should add a filter for the store to show only games with controller support, filter that would be always enabled in the version of the store for the console.
When Apple wants to see games supporting some new feature, hardware, accesory or OS, Apple doesn't touch the games, instead they typically use three ways to 'convince' 3rd party devs to adopt their new stuff:
-One is to add a new dedicated filter, or dedicated featuring in the store for games that support this new stuff if it's something optional, so devs implement it to get some visibility in the ultra crowded store.
-Other one is to require mandatory support of that stuff on the checklist of things that they require to the games that get submitted to them to be released or updated, so starting a certain day no games get released or updated unless they support that stuff.
-Other one is to say that they will remove all the games of the store that don't support that stuff, so devs get fucked off if don't update their game.
Also, well this is more in general but, I don't see why people are underestimating Apple's ability to deliver a proper games console. I know the Pippin is a meme, but it was also 26 years ago, from a really bad spot in Apple's history. If they managed to turn around in general, what makes you think they couldn't do such with a video game system? They obviously have a lot more resources and experience since the '90s, and a lot more data on the market to have observed and learned from.
Pippin was a failure, but they are now in a very different position.
Looking at their smartphone, tablet or watch hardware sales I'm pretty sure Apple's console will outsell Xbox, PS and Switch. Even if we only look at their mobile gaming userbase and revenue, iPhone and iPad already are the top performing gaming devices.
If they release an Apple gamepad (compatible with iPhone, iPad, Mac and their console) and related store (or proper store section for gamepad games on iPhone, iPad, Mac) they already would get way more support for traditional gamepad based games. And releasing the console, will get even more. As in Switch, AAA support will depend on horsepower available.
Given their brand power alone, I strongly doubt a new Apple gaming console would perform anywhere near as badly as the Pippin, and I think that scares some people. That said I think there are other reasons why they aren't seriously considering a dedicated gaming console: what could Apple address in terms of the gaming market that Sony, Microsoft and Nintendo aren't already addressing in one way or another?
What can Apple provide that they can't, which benefits the market both for developers and for gamers? What value proposition in terms of content, pricing, and experience could Apple provide that the Big 3 cannot?
If they can't answer those questions clearly and concisely, then you're not going to get a dedicated gaming system from them. Period.
As happens with Nintendo, to release any product with the Apple logo on it means millions of people will go to buy it just because has the Apple logo on it. Doesn't matter if the competition has better specs or content, doesn't matter if heavily overpriced, doesn't matter if the user doesn't need at all the things it adds compared to the other ones.
Many Apple fans will buy it only because it's an Apple product. And they only need a small portion of Apple fans to turn it into the best selling console ever. So they will become the most important company in gaming, even beyond mobile.
It's confirmed that Google, Microsoft and Apple spy their users to sell data to marketing firms and to multiple intelligence government agencies from multiple countries, but Sony and Nintendo don't (or at least isn't known). Sony and Nintendo combined are over 200M users that maybe aren't properly spied while playing, so their clients would like too cover that too.
Then there's many iPad and iPhone games playable with a controller, but using a 3rd party one when they could be using a $400 Apple gamepad instead which would provide many profits for Apple not only from the gamepad, but from the related revenue increase of these games.
Same goes with playing on the tv: there are many ways to play your iPhone and iPad games streamed on a tv, but for Apple it would be better using a $2000 Apple console. Specially to get a chunk -if not all- of these ~300M console+Steam players into the Apple ecosystem.
I mention Mac because since basically their console, smartphone, tablet and PC will have basically the same OS, hardware and games, it will mean that Mac finally will get a good amount of gamepad based games, something always Mac users missed and the main reason of why many people did got a Windows PC instead.