XboxPC is the MSStore but just for games.
You dont pay for online on the MSStore.
The idea is for devs to actually put games on the MSStore as some devs just never bother.
So when you boot the stripped Win11 whatever its gonna be called, the first store you see is the MSStore but its nothing but games, if those games are fucking Sudoku you are swapping out of there ASAP.
So they are trying to get more devs to put their games on the store so atleast the front page has titles that are currently popular.
If they can legit get Win11 stripped down enough with a good front end that handheld machines and maybe even pure gaming PCs start seeing it as an OS worth using, they might be able to "trick" people into using the MSStore purely out of convenience and being front facing.
Remember how many of your friends/family legit used Internet Explorer without pause?
It was there and it got them on the internet even if FireFox was leagues and leagues better already.
Imma guess MS is trying to get gamers to follow the same path, when you boot your PC/Handheld the games you see are from the MS Store, they sell you gamepass promising 100s of games so you just subscribe and say fuck it.