None of this post makes any sense.
Steam consoles are niche at best, only available at Steam's own store. It will never be mainstream.
If Sony even feels like their MAU and their PS store is losing steam because they release their stuff on Steam...they will just stop doing so.
What they get from PC is nothing compared to what they get from their own ecosystem, subscriptions, etc.
And "stupidly enticing their customers to migrate to PC"? As we speak PS5 is above everything else on Amazon in almost every place on earth. (including even Switch 2 in almost every country i checked). Next year they are getting Wolverine, Saros as PS5 exclusives. They will release Marvel Tokon and then GTAVI will release on their consoles with a marketing deal (which they have for GTA for a while now). There's literally no signs of the market shifting away from their platform. If anything it seems like this gen will last longer than the previous one.
They also barely released a PC game this year. Stuff like Gran Turismo 7, Demons Souls, Astrobot, Ghost of Yotei aren't there. Spider-Man 2 and Ragnarok did a lot worse than its predecessors on PC even if released much closer to their initial release date as well. Sony also removed any mentions of PC gaming from their quarter results for 2 quarters already.
If anything Sony would be smart to sell their games through a PC storefront where they get 100% of the revenue, crossbuy with PS consoles as well. And that's the rumors as well.