Now that's how you do it.

There is no "API" specific to implementing FSR, it's just code that will run on "any" GPU using already existing graphics API.
I saw that both MS with Direct X11 and Direct X12, and Vulkan were supporting it, which is how I assumed it was going to be able to be used on the wide range of GPUs regardless of make, as pretty much every single PC game uses either Vulkan or DX.
On top of that the Xbox uses DX12.
We then had Sony who hadn't at that point supported it directly.
With what was said about Vulkan and DX I guess that Sony had to make their API support it, which it appeared they hadn't.
I was never saying that the PS5 couldn't do FSR, of course it could.
My initial thought was that Sony was going to roll out their own Temporal Upscaling tech, and we had already seen Insomniac use their own solution and it was pretty good.
We also see how UE5 has a version of Temporal reconstruction which works well.
Anyway, it kinda makes we wonder why MS and Vulkan even bothered announcing that they were going to support it when it doesn't even need them to.