speak for yourself. keep your mods. let me pay a dollar, soon to be ten, but that's besides the point, to play a game for a few days rather than paying full price. yes, i know this is CAG, but i'd rather pay a buck now without access/mods than wait for a game to be bundled.
If Vampire: Bloodlines 1 was on Microsoft Store - yeah, it would never work, without modding allowed, game comes attached w/ Wesp's patch, or brand new official fixes from Activision. It just doesn't work out-the-box on W10. Unless it came attached w/ Wesp's unofficial patch; Activision went in and officially fixed it themselves; or whatever the case - good luck getting it going on W8 and W10.
Though, I'd also probably guess - and I could be wrong on this one, who knows [shrug] - if a game's on PC Game Pass, Microsoft likely curates this more than Steam and would likely make sure it works, out-the-box before putting it up there on Game Pass.
I definitely get wanting access to games NOW for much cheaper (i.e. $1 first-month, $5 in Beta Phase, $10 in Official phase starting Sept. 17th). At $5 - for me, it's a no brainer; it's worth it. A pain in the neck to deal w/ its restrictions - but still, worth it. I easily get $5 a month worth here.
At $10 - eh, maybe I'll sub a month here or there, depending if there's really something I want to play ASAP is in there and can marathon it if it's a longer title, when I have say vacation time, days off, and whatnot.
But I do also wonder about save files and folders; especially in case DLC's aren't in the Game Pass version. RAGE 2 on Game Pass and Outer Worlds do NOT have the DLC's attached right now (man, I wish Gorgon was on Game Pass right now, I'd so play it) - meaning, you want them, you might have to wait for them to hopefully end up on the Pass; or go buy the game & its DLC's somewhere.
I also don't think all versions seem to be the same on Game Pass and other versions (Steam, GOG, etc). For short games - eh, this might not matter that much; since they're short and quick & easy enough to re-run through.
Though, this really could be important for long games, especially RPG's of that sort - as I don't think some of these, I can just finish in say one month's time. Some of these games are royal time-sinks - talking 40-50 hours at least.
My saves/profiles from Night Call Xbox PC Game Pass version (played on Game Pass), for example, just DO NOT work on Steam-version (wound-up owning the game from one of the Humble Bundles).
Though, my RAGE 2 save from Xbox for PC Game Pass....that save works in the Bethesda version of the game - which is great.

Was easy enough for me to pick up where I left up, basically.
And we all know Metro: Exodus (when it was on Game Pass) had all kinds of other issues that weren't in Epic version too. So, until I get Metro Exodus on say Epic, Steam, GOG - who knows if PC Game Pass/Xbox version's save will work w/ that too.
Also, I'm on Game Pass playing Wasteland 3. Some 20 hours in or so. Hopefully, I get this game done soon...before Oct. 8th (next billing cycle). If not, well - hopefully, when I likely buy the game, saves from Xbox for PC Game Pass work on other versions of the game (Steam, GOG, etc). Or, or course, when I do re-sub, I'll just finish it up then.