This is what I'll say from a dev perspective on the merger.
You'll notice more and more indie devs skipping Xbox altogether. This is because it's increasingly harder to sell games on that platform. And so the only on ramp to making an Xbox port is by getting a gamepass deal.
Getting a gamepass deal is extremely difficult. I've been going through the process for well over a year and a half now. Sometimes you luck out and you have a smash hit and get an easy gamepass deal. But for a majority of devs, we're all fighting each other for the increasingly smaller bite of the pie.
Now because it's just Xbox it's easy enough to focus on PC/PS/Switch and make a go of it there. And of course there are a number of other subscription based offers, of which I've been a part of, and they're great. And I know that when you're on gamepass it's also a net win for yourself because it rarely damages other platform sales.
So what's the difference between PS+ on PS and gamepass on Xbox? Gamepass is very aggressive- you get day one AAA titles, something no other service can offer on a consistent basis (well, consistent in the kind of lineup that MS has year to year). At some point it makes less sense to buy games on that platform than it does subbing to them. And that's where sales can't really live harmoniously anymore, and you start to not just want a gamepass deal, but absolutely need it to survive.
Perhaps it's contradictory to want gamepass to exist, but not be too successful. I dunno. But MS gobbling up a massive company and putting all their titles under the gamepass wing just makes it more and more difficult to survive out here.