A lot of older PC games can run just fine on modern phone hardware. I’d buy a SteamOS version of a phone that has some modular or built-in set of buttons and analog sticks. I don’t know how the app ecosystem would work for sensitive things like banking but it’s mostly a minor issue for me.
As someone who’s used a couple phones running SFOS, it’s worked pretty well. it’s not perfect/has some quirks but the UI is really nice and there’s a community of people making apps for it and the like. Plus it’s Linux which is nice.