An important ingredient to Proton in DXVK, which was a new project and the author of which was quickly funded by Valve as it greatly improved performance, especially AAA+++ titles. Secondly, Valve funds Crossover, the commercial entity already responsible for large parts of Wine. The heart of Proton is thus free and libre software.

What sets Proton apart from alternatives like Lutris, which also configure Wine, DXVK, and other components, for you, is that it is zero conf, integrated in a tool (Steam) you probably are already using if you play games. Personally, Proton is the only tool where the autoconfiguration actually always works.