No simplications at all. And come on you are pratically rewriting history here.
Saturn died with less than 10M worldwide. Dreamcast the same and dropped dead even faster. N64 used cartridges and their production cost was higher than that of CD-ROMs and storage capacity was lower. It was a stupid mistake for Nintendo, but they didn't care as long as their games were selling. They lost Square for this, just google it. They had a serious rupture at that time.
I'm not rewriting anything; I'm actually giving context that you want to pretend doesn't exist. The final conclusion of things might be as you say, but the problem with some people when they talk about consoles in historical context is they lose the subtlety of things, the nuance and context of how things specifically led up to certain moments. That cheapens the discussion.
Saturn was still a competitive entity in the Japanese market from 1994 through early 1997. The N64 had very strong sales in the West and got a lot of specific Western support during the generation. These are facts. You can't act like all the support Sony got that generation, during the first half at least, just naturally gravitated to them due to their mere existence. Deals happened. Talent was poached. Preferences were built. Financial and resource might competitors absolutely lacked was leveraged to pull in support and lock deals down.
And all of that led to what essentially became a form of consolidation: content consolidation.
What I'm saying is devs and publishers were really independent and they chose what were best from them. Not everything was about money, but you can't blame them to chose a platform where most of their fan base were.
Uh, what fanbase was there for Final Fantasy on PS1 before FFVII came out? Was there a Sony console before the PS1 that got Final Fantasy releases I should be aware of? Because it almost sounds like that business deals were established in attracting certain devs/pubs and IP to Sony's first platform that lacked organic presence of fanbase for those IP, and those IP now being established on their platform got the fanbases to gravitate to that platform.
Almost as if, people will go where the games are, the platform itself be damned

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It wasn't a locked content, they could've go to any other platform at any time.
Tell that to Shinji Mikami and the kerfuffle that was RE3/Code Veronica. I guess Sony mandating three numbered RE entries on their system wasn't a factor whatsoever in what was meant to be Dreamcast Resident Evil 3, turning into Code Veronica

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One of the few that still has that mentality to stick to one platform is Atlus, for example. They're are slowly open up, but it's a perfect example of they can go multiplayer, they just don't wanna.
How do you know they don't want to? You do realize the mainline Shin Megami Tensei games have been on Nintendo for decades post-PS2, right? Isn't that a non-Sony platform? So they are already multiplat, and have been for a while now. Never mind they were vehemently multi-plat pre-PS2 as well, releasing multiple games on the Sega Saturn and even a few on Dreamcast, while also supporting PS1 (and before that, sticking with the SFC and Famicom, the only time when they were actually a single-platform dev/pub btw).
Not true.
ND released Crash Bandicoot 1, 2, 3 & CTR as PS1 exclusive games before being aquiring to make PS2 games like Jak & Daxter.
They made Way of the Warrior for the 3DO well before the Crash Bandicoot games.
Psygnosis released temporal console exclusives for PS1 like Wipeout or Destruction Derby that some time later got ported.
These were due to pre-existing contracts.
They also made many other full console exclusive PS1 games like Adidas Power Soccer, Chronicles of the Sword, Destruction Derby 2, Formula 1, Colony Wars, Lomax, F197, G Police, Tenka, Rush Hour, Shadow Master, League of Pain, Rollcage, Rollcage 2, Wipeout 3 and many more before being acquired to make PS2 games.
They were acquired by Sony in
1993, your dates are wrong. And before doing content for Sony, they did games for various microcomputers, including Ballistix, Obliterator, and Shadow of the Beast.
3% of 1600 is 48 million games for PS4, which is very generous. We don't know the exact number of total of PS4 games sold, but we know while ago was above 1622. It may be over 1700 and will be higher at the end of the generation. I mentioned 'less than 3%' to throw and approximate, but less than 2% at the end of the generation would be more realistic.
What criteria are you using to assume that would be more realistic? Estimates put Fallout 4 alone at between 20 million - 30 million copies sold across all platforms. Assuming an even split between PS/Xbox/PC (it would in reality lean more towards PS and PC over Xbox, btw), that's at least 6.6 million - 10 million across PS platforms, and Pete Hines has also said FO4 is their most successful game ever, likely in revenue. So even if Skyrim has sold more copies, they have generated more revenue (and profit) from Fallout 4, comparatively speaking.
Never mind that when talking Bethesda you're also talking Zenimax which includes all the other IP such as Wolfenstein, Dishonoured, DOOM, Quake etc. Over the period of seven years, cumulatively speaking they have likely reached around that 48 million figure.
It's a good number for Zenimax, but looking at the growth in Sony's business, this ~2% of the game sales will be compensated with the growth. Sony won't miss them. And again, it was estimating they sold ~50M PS4 games which I think it isn't the case at all.
You haven't provided anything tangible to say why you don't think that to be the case tho so
Regarding Sony's numbers, I'd say in recent quarters they mention the % of 1st party sales (for that quarter, not in total) and don't remember the number but I think it was something like 18%. Which in the scale of the amount of games sold in total for PS is pretty impressive.
That was 18% for that fiscal year, not 18% in totality. Considering there were years where 1P output was very quiet or tepid compared to what really started to get going 2016 and onward, we can probably average that totality rate out to between 10% to 12% of that total software LTD sales total. Which, yes, is still great, but are we now talking about absolute numbers or percentage ratios?
Because if you're being fair here, they (and Microsoft) are clearly behind Nintendo in terms of the latter and also behind Nintendo in terms of software revenue and profit figures relative to their percentage ratios of 1P content sales in the software ecosystem (Sony and MS 1P games get price cuts, sales, and packaging inclusion in certain SKUs much more frequently and quickly than Nintendo 1P software).
What matters when talking about games are their gaming divisions. MS having trillions as corporation didn't help them to catch Sony in 20 years.
You also don't need to "catch" someone else to be successful in your own right. Did you forget this part? Nintendo hasn't "caught" Sony in 20 years either if talking about home consoles, but they're mighty healthy and in some ways more successful than Sony. If you wanted to include brands like Minecraft into the equation, Microsoft's gaming division is actually quite strong in its own way and can claim to have an IP of revenue potential much higher than any single Sony IP.