I was very sceptical at first but when I tried Doom 2016 over the wifi on my tv I was realy impressed.
Just think about it for one second, the game runs over the wifi on 30$ Chromecast on my 10y/o TV and it looks great with almost no lag, I'm an avid FPS player and it's really ok lag wise to play on Stadia.
You have no physical copy, no downloads option and no recourse; you're effed.
And it doesn't have to be the end of Stadia scenario either. You lose access to your account and you are similarly effed, the algorithm decides you are suspicious and, you guessed it, you're effed too.
The idea that you pay for a game and get a video stream is a scam.
It's impressive and way better than I thought it would be when they first announced the product.
I recommend people try it out for free and judge for yourself.