I think almost every Microsoft product has a FOSS alternative (that works in windows usually too) if you want to get away from them. GamePass/The Xbox app/Windows store doesn’t, but that’s almost it. If there isn’t an alternative, it’s not unlikely that it’ll work through WINE. What software specifically are you looking for?
There are alternatives for office. LibreOffice, which has been around forever.
As for anti-cheat, yeah that’s up to the devs. Easy Anti-cheat supports Linux in the latest version, but it requires developers to implement it. I’ve been playing Hunt Showdown and it’s fine. Counterstrike obviously works. I’d say on average, most anti-cheat is fine. It does require actual effort on the devs though, unlike games that just run with WINE/Proton totally fine most of the time without them doing anything.
LibreOffice is great if you don’t need perfect compatibility with Microsoft office. If you do, the only good option is, well Microsoft Office.
