Earlier quoted context omitted.
the latency is also terrible. even with a single player platformer game I couldn't make do with it.
Steam link games don't have latency compensation since the games are unmodified. I assume that stadia games will have latency compensation, so should be much more playable.
No matter how good Google's CDN network is, you can't compete with sub-1ms in-network round trips. There's not really any clever "latency compensation" you can do here.
Even if you rewind state to apply input, which games probably won't support anyway, that still only helps you close the gap added by internet latency. A gap that in-home doesn't even have in the first place.