Now if you extend that reasoning and get to a point where everyone using a PlayStation console was buying all or most of their multiplatform games on the platform and almost noone is only buying 1p games, this means that Sony could then sell the console at a greater loss knowing that they'll have a much larger chance to have a significant profit from each purchaser of PlayStation console. At this point they don't have to worry about a person that only buys 1p games generating a loss or at best a miniscule profit. This could potentially lead to a more capable console than if they had to worry about people that were only getting a PlayStation console for the exclusives and nothing else.
If you look at Microsoft, they aren't selling as many consoles as Sony. But anyone that buys an Xbox console is likely also buying their multiplatform games there. Anyone that buys most of their multiplatform games on PC are unlikely to be getting an XBS system and thus reducing profit margins there. They are maximizing profits with a lower investment cost (hardware).
There is, of course, still one group of buyers who are non-optimal, but there's not much you can do about that other than hope that these people convert to XBS consumers. And this would be people that get all their multiplatform games on PS5 but got the XBS console just for MS's 1p exclusives. Of course, even there it isn't all doom and gloom for MS if those users end up getting Game Pass as the cheaper way to play MS 1p exclusives.
Anyway, the whole thing is that it's not as simple as just thinking about whether someone buys a PS5 or not. When looking at a why Sony are interested in releasing games on PC, one should dig deeper and try to think of why Sony are doing it in the first place. And there are of course multiple reasons. As has been pointed out in the past, one reason is to potentially draw people to play games on a PlayStation instead of PC. And some people might switch, whether due to cost or convenience or whatever. But another reason is to potentially (at some point in the future if it doesn't negatively impact PS sales) have people that only buy 1p games on PS, instead get those on PC so that PS consoles only sell to people that buy all or most of their games on PS.
That's the ideal world from a corporate profitability standpoint. A healthy PS ecosystem where everyone with a PS console is buying all/most of their games on PS. Then at the same time, get additional large chunks of revenue from people that traditionally only bought 1p games on PS instead getting it on PC along with potentially millions of additional sales from PC gamers who would never get a PS.
And on top of that, since your PS exclusives are also on PC, if a PC player suddenly can't afford to game on PC anymore due to the high hardware costs, he'll be looking at a console. If all they've had exposure to are Xbox console exclusives, they'll likely get an Xbox. But, if they've also had exposure to PS exclusives, well, that decision just got tougher with them likely going to PS due to current disparity of 1p exclusives (Sony currently have more and arguably better exclusives).
Regards,
SB