They're not behind in server coverage, certainly Azure isn't. MS has more data centers in more places than anyone else. And xCloud has the same number of regions as Stadia, but they have South Korea, which is apparently doing very well for them, and Stadia doesn't. And while they haven't ramped up their server blades as much as they could have because they're transistioning to Series X hardware, and that transistion will likely be slowed by component shortages, I don't think they've got any particular shortage there atm.
Of course, MS does not, currently, have anything lined up to allow the streaming of PC games though. That may change, but there's been no announcement of anything around it. So while streaming is a solution for playing console games on a Mac, it wouldn't work for playing Paradox games that aren't ported to Xbox first. And as yet there's no mouse and keyboard support for xCloud. So that would also need to be addressed.
I do think Paradox would be a good buy for them though, if they want to grow their PC offerings. So would Sega.