Unmotivated? Its a literal checkbox in the anticheats that games package to enable running in Proton. This is not Valve's responsibility, but idiot or lazy game companies/devs.
Secure boot is what I think you're thinking of because of Battlefield 6. But as I understand from just skimming it, its handled a bit differently in Linux than Windows, so unsure of how that could be handled or adapted for native Windows games.
Finally!!! Playnite was amazing when I used to be on Windows. Unfortunately no Linux tool yet has the extendability and usefulness Playnite has. Looking forward to seeing this on Linux eventually. It really is amazing for unifying game libraries and has decent almost Steam Big Picture-like skins too.