Also super fast loading times. Playing e.g. RDR2 on a physical console, by comparison, is painful.
Stadia worked absurdly well. One of the beta games was Thumper, a demanding rhythm game (I might be the reason why it was in the beta lineup actually). How well did that work out? Well, the latency made it hard to play... until I switched my TV to so-called "gaming mode". And then it was fine.
No kidding. The TV was introducing more latency than Stadia itself.
I also once tested it on hotel wifi. It worked great.
(Mind you, this was in Europe. YMMV.)
The business model however was terrible and killed the product IMO. Which, honestly, good: Stadia would have killed video game archiving efforts. If a publisher folds and Stadia and similar platforms stop streaming its streaming-exclusives, then those games are gone. Not worth it, no matter how well it worked.