Wine existed before Valve even if you weren't paying attention.

I've been messing around with Linux for games for over a decade. Proton was a revelation, but in addition to that the Linux desktop system stack has had Valve money pumped into it, seeing a huge amount of improvement. Video drivers, KDE, SDL2 additions to the kernel and much more.

Even Proton is technically managed by Codeweavers under contract by Valve, who are the primary contributors to Wine.

I’ve used wine since its first releases but it was never able to handle most games, Proton really changed things significantly and Valve has dumped megatons of effort into quality and completeness of experience. It’s fairly disingenuous to assert pre-Valve’s investment wine as meaningful comparable to post Proton wine let alone Proton itself.