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.
This is what is known as a “hypothetical question”, the idea is that your don’t answer based on your actual situation, but based on a hypothetical one.
So, now imagine instead that a wizard teleported your current phone into the plane of fire, destroying it, and you have a gift voucher that can only be spent on phones that’s “one free phone” and there’s a Steam Phone in the shop. Would you want it? Would you buy it?