Runs great on Stadia compared to PC (in my experience playing on both platforms). Google needs to make something of this. I even tried running it from Chrome on my old MacBookPro 2015 and was thrilled it worked and was a great experience.
I suppose you played on Stadia from a friend's account right? Otherwise you would had to have to buy the game twice, once in GOG/Steam/Epic and another in Stadia. For that reason if I were to consider cloud gaming I would prefer something like Geforce Now or Shadow rather than Stadia or Luna.
I suppose I need to explain myself. Alas I purchased the game on PC/Steam, Stadia and PS4. And yes I play on all of those, depending on what OS I am booted into and running and which part of my house I feel like playing.
Interesting... it sounds like an odd choice though, because you wouldn't be able to progress the same story in all 3 platforms, as you can't sync between them, right?
Also, I really think that Steam is the superior platform at the moment in terms of features compared to Epic and GOG, but in this case I think it would be better to buy it in GOG since not only all of the money goes directly to CD Project Red instead of 30% for Steam, but also there's some goodies if you buy it in GOG...
Anyway, I think if you bought the game 3 times you more than make up for that 30%.