Nvidia Shield would work for that with the Geforce Now service. Pros: don't have to pay unless stuck in queue and want priority or higher quality. Cons: have to own your games elsewhere for Geforce Now to be able to stream it (for license reasons), and it's about the same price as an Apple TV.

Game Pass Cloud does work on some smart TVs, mostly the latest ones from Samsung so if you got one of those then you don't even need a box. Amazon Luna is the same. Samsung TV.