Please reply in short: Why ? PC got it, Next Gen got it ... why not Stadia?

My guess is, that the Google Stadia - Servers are powerful enough to render the game at 4K 60 FPS with a FOV setting available. The "network requirements" wont change as the VP9 - Encoder has to produce the same video stream send to the players. I also recognized that even if your video stream is for example "only" 1440p 60 fps, internally the game is still running at 4k (because if you keep pressing the F12 - key, the "video clip capture" is captured in 4k resolution) So basically, the "performance based on their hardware" can be negated as the same hardware is running higher demanding games on Google Stadia (you can get Cyberpunk in 4K with 60 FPS running on Stadia servers and this game has much higher requirements compared to Destiny 2). And the "network requirements" won't change as the VP9 video stream will come with 40 ~ 50 MBit/s when playing at "highest stream quality" no matter if the picture will show a higher or lower FOV (like all games played will come with that bandwidth used when playing any game). Sorry @TuxyDoh, but that argument doesn't seem like a valid answer to the question why and more like a pretext for the non-technical gamers.