I, a developer, have never heard of Proton. Googling Proton, I only find Protonmail, and googling "Linux Proton," Valve's Proton is not even the first result. If you are not terminally online keeping up with Linux distro discourse, it's also difficult to even recognize any of the newer names and players.

Linux is not even remotely considerable as an option for the average consumer, which is fine and fully intentional with the audience and goals Linux distros serve.

You could even consider this a strong positive, because a Linux distro geared towards average consumers would probably be an analog to Samsung's take on Android. What makes your experience with Linux good is that it isn't catering towards a wider audience.

You've probably heard of the state of Mac gaming, if you've played video games much at all.

Linux has twice the number of active Steam users as Mac, with probably very nearly all of them using Proton to some degree: https://store.steampowered.com/hwsurvey/Steam-Hardware-Softw...

Personally, I've actually had noticeably better compatibility on Linux with older games, compared to Windows. And every single one I've been interested in for the past several years works flawlessly on it. (I don't enjoy most AAA games, so my sample is definitely skewed, but it's a fairly common result)

You, a developer, just happened to not know a very well known software. This fact is not as meaningful as you believe it is.