You do realise the PC space means all software providers, publishers, studios making apps, game publishers, etc.
They *could* put a lockdown on everything and just be an outward brute to everyone, but we all know how that worked out when they tried their EEE strat, so them going from a subtle strat to an outlandish one would get shut down so much faster.
PC in general is so much bigger than you think you know, bigger than anyone here knows, and I'm not on about the gaming sector, I'm on about everything else (yes literally everything else within it's sphere). MS cannot afford to buyout or control absolutely everything on PC, it's both impossible and entirely impractical (Which is why they have their OS, the cloud and some services, instead of hw, and literally everything else anyone else has made for and on PC, past present and future, because that's just not possible.
I'm legit trying to mull over this ability to somehow own/dominate an open platform, and it sounds so bonkers, like not a "whoa man, far out", I mean as in "wow, not possible, why we we even trying to think of this?".
Despite what others will tell you, Mac, Windows and Linux, as well as Amiga, are all OS's that are used for PC's, so regardless of Windows existing, MS would still somehow have to dominate/own Mac OS and Linux, as in prevent any and all growth, because time changes everything, things grow, and dominance can certainly wane, so for them to dominate all of PC, they would have to eliminate or own those following OS's, or risk them growing and making their "dominance" a non factor or "whatever".
I don't understand what you're to say here, really. Just literally hours ago the EC ordered Microsoft to uncouple Teams from Office because Slack, the product MS copied, lost all of its lead to Teams after MS flexed its muscle and leveraged its dominant position to promote their copycat product. MS is a convicted monopolist and a repeat offender, they will abuse whatever power they're handed, whether they're successful at this or not is a different matter; one the CMA isn't keen on finding out.
The funny thing is that MS didn't protest the EC decision at all and complied immediately, because as a repeat offender, they know better than anyone how they challenged similar decisions in the past and lost.