You might want to look up how Proton actually works? Proton doesn't need Windows. It doesn't emulate the games either, it doesn't emulate hardware in some way. It isn't a copy of Windowsrunning inside Steam or something.

It's a compatibility/translation layer, translating the API calls from the games into calls that will work on Linux, on demand as they occur.

No Windows install needed.

But you really sold your confidence! A for showmanship! 👏