The 2013 Steam Machine is as different from this device as it could possibly be. Proton didn't exist back then and Steam Input was still in (relative) infancy.
Both are console-sized x86 based computers that can run Windows or Linux. Both even lack a 3.5mm headphone jack (maybe that’s too old for a 2026 computer though). Both have a low TDP that means they will never compete with a traditional gaming computer.
I’m not sure what Proton has to do with anything.