For me Stadia reintroduced me to gaming and I am more than happy to have the opportunity to play BG3 without having to wait 5+ years before budget laptops can handle contemporary games. I don't think it will shut down, but there's always the possibility it migrates to a different service or changes into a white label service where different publishers can have their own netflix-style game-streaming channel (e.g. ubisoft+). So from the perspective of someone whose last console was a PS2 and last 'gaming rig' had difficulty running Rome total war 2, I don't mind that it is equal to previous gen rather than next gen in terms of graphs as anything better than what I knew is shiny and futuristic to me.
I do feel the need to correct you on the subscription comment you made though. The service is free, you buy the game and have limitless playtime. The subscription is optional and includes the possibility to stream in 4k and surround audio as well as a collection of free games you can claim and always can play once claimed (even after re-subbing, you just regain access to the same games in contrast to xbox live's rotation system). Since I have no screen that can do 4k (or hdr), I don't see a reason to pay for the subscription and felt the need to correct you.
Edit: some afterthoughts and extra speculation.
I would also be surprised if stadia would be the issue given how the cyberpunk release was a total disaster, except on stadia where it ran well (in so far a buggy unfinished game can run well). I think it's more an issue of prioritizing and assigning dev teams to where they have the most impact, aka bigger playerbase, and thus a choice to put the stadia development on a side-track - possibly outsourced to one of the new studios - meaning they first make the PC version, then move it to the smaller mac team and the - probably even smaller - stadia team to port the main version to these respective platforms. As far as I know Stadia simply runs on Linux so it shouldn't be this much harder given BG3 was developed with this in mind from the beginning. Some updates ago Larian posted something on Twitter about Stadia's verification process being very strict (and slow) but then in the next patch they ensured it released at the same time, so if they want to, they can, I just fear they don't really want to anymore.
Apart from being disappointed by going trough the hype build up, then a week of spoilers and waiting without news, which although not nice I could understand, the fact that the other platforms are already receiving hotfixes for a patch I still can not access is very demotivating to stay involved with BG3. Not blaming Larian for this, but i think they should be aware of this, as I imagine that even if the Stadia playerbase is smaller, it would be stupid to ignore them as I feel it is an interesting demographic of people pulled back into gaming, who although not willing to spend the money on expensive hardware, are probably in a point in their life where they are more affluent than your average teenage gamer who needs to ask his/her parent for money for new games. Moreover, i feel that they are fairly overrepresented and quite active on these forums and reddit relative to the platforms player base compared to PC. i think this could be due to a lot of infinity game players and fans not having the means or will to update their hardware have the possibility to play BG3 nonetheless on stadia. So perhaps from a marketing and EA development perspective these are good qualities for a costumer/tester population: dedicated fans of the older games, hesitant to buy hardware but probably in a better financial situation on average, more 'in it' for BG3 than for gaming in general. etc etc etc bla bla bla
just give us the damn patch please !