As someone who used to make async multiplayer games I think Stadia is a good fit currently for that style of game. Using it for latency-sensitive AAA games seems like a decade or two too early for the tech.

Cloud gaming has huge multiplayer advantages because you can skip the whole network stack and build your game for couch multiplayer, yet it's still playable over the internet.

Combine that with the deep pockets of F2P gamers, and Google's existing relationship with these devs via Google Play; I have no idea how they missed this.