I don’t see how this is possible if they are sending player input to a server somewhere with a 50ms ping. That’s a full twentieth of a second, not counting any lag at all from the server side.
I guess if you play an MMO or something that doesn’t care about lag it wouldn’t matter but I don’t see how you could play even a simple fighting game like Street Fighter 2 with that kind of lag, except at the most basic level.
As for a game like SF, I am not sure. They have MK on Stadia and I hear people enjoy it but I don't know what the latency is like.
This is with wifi hitting a local router, to a separate wifi access point, then wifi to my desktop. None of the network equipment is “gaming grade”.
FWIW: At 60 ms (due to a misconfiguration) super meat boy was unplayable.
The reason some people think that is absolutely insane and ridiculous is simply perception. I switched from 100 Hz CRTs to 120, then 165 Hz LCDs. Console games to me are unplayable already. Obviously, Stadia in it's current form is entire useless to me, no matter what game I'm playing because it just feels bad.
However, people who mostly played 30 FPS console games their entire lives, can usually play on stadia perfectly fine. The input lag isn't that much worse.