Ah cool, thanks for looking all that up. I knew Proton pre-dated Steam Deck, I just wasn't sure exactly where in the timeline it fit between the original Steam Machine launch and the release of the Steam Deck.

It's kind of a shame that Steam Machine failed, but in many ways it was a little too ahead of its time and its failure brought us to the Steam Deck which is a much more sensible approach.

Ultimately none of this would have existed without Wine and ironically the Microsoft app store (or whatever they're calling it these days). The threat of MS getting a stranglehold on program distribution on Windows the way Apple does on OS X and iOS was enough to spur Valve into putting significant effort into making Linux a viable gaming platform, something we're all benefitting from greatly.

People seem to be downplaying somewhat how significant an achievement this is for Linux. The thing is, for most programs you can find alternatives because the point isn't the program it's what you do with it. People don't use Photoshop because they enjoy Photoshop, they do it because they want to create something, which means if you can create that same thing using a different program then you don't need Photoshop. On the other hand games are an experience. The point is the game. Sure you can play a different game, but that's not an Apples to Apples thing as the experience however similar isn't the same. That means games are uniquely placed as a roadblock for migrating away from a platform, something consoles with their exclusive releases have known for a long time. Giving people the option to play the exact same game under Linux as they can under Windows is massive because there really isn't any other way to solve that problem.