I just saw this thread and comment. I tried something Stadia when they started making it free. About Stadia, god, it shows a lot, but a lot that they have barely given feedback. Needing yes or yes Chrome is a nuisance when you are one of those who use Firefox. Another problem is that it doesn't recognize controllers well if they aren't the classic Xbox XBox with XInput, but I don't use a weird one, but a Nintendo Switch one that even Steam and many games recognize as a base, and I can't use Steam with the app native, which has little app and redirects you to Chrome.

Regarding streaming, well, I noticed less lag than I expected according to the memes. Of course, I was playing Gylt (what other game was I going to play on Stadia taking advantage of the free trial?) and in these types of games it is not very noticeable. Youtuber Stumblebee commented with his experience in Samurai Shodown that it is far from being comparable to playing in local mode, so at least fighting games have a hard time using Stadia in events like EVO. Oh, and another streaming problem: the black colors are blown out and it hurts to see them. For better understanding, this video by Tom Scott explains it well: https://www.youtube.com/watch?v=h9j89L8eQQk Perhaps in another game it would have been less noticeable, but in a horror game with a lot of lack of light, it hurt to see it.

And the streaming of games, like downloadable games, is something inevitable that we will eat whether we want to or not. Companies have been since the Atari 2600 wanting to cut out every possible middleman and expense. That's why they want services like XCloud or PlayStation now, to save themselves from having to distribute games and risk losses. But if the physical and digital formats still coexist, streaming will be another one and it will only be exclusive if there are many checkbooks involved, as with the Gylt (but luckily in a year or two we will see it on PC, Switch or PS4/5) , or really something only possible with the cloud, as we say... An MMO or a very big battle royale. There is already a mode of 40 simultaneous humans in a GRID that exists in Stadia (I say one, without specifying, because Codemasters does not stop removing and rebooting them) and I suppose that is the trend that we will see with this type of game.

Right now the thing is very in its infancy but it could be another alternative in the near future. I almost see it more as a kind of "cyber" than there was at the time to go play a casual game but now telematically. A solution for people who on a specific day want to play a game in particular but do not want to invest in powerful consoles or computers because they consider that the cost is not worth it and in this way they pay a couple of euros to play for a few hours and ready.
But for enthusiastic people who spend hours and hours playing, at the best resolution and good refresh rates I see no way out now or in the future.
The big hardware industry wouldn't let it lose millions of sales anyway either.

In short, it is good to have options in the sector for each one to choose their best option, but of course it will not be the end of physical devices.