My laptop is a basic spec potato, so xfce on xubuntu.

Not strictly proton, but for wine, you can see here (https://appdb.winehq.org/) that it supports more than just games.

Problem is there is a total lack of Linux native games out there. Even major OSS games these days are not exclusively Linux native, but cross platform.

Good OSS games also tend to be niche. Like, for me, Simutrans and openTTD. Tycoon genre like this are no longer as popular as it once was