Has it really been that long? Apparently so. Valve originally announced their rebranding of Steam Play with Proton back on August 21st, 2018. Seems like a good time for a quick reflection being halfway to a decade old now with the tech that gave rise to the Steam Deck.
I mean, enthusiasts made it work. Compared to nothing, it’s a hell of a lot better. PlayOnLinux was also popular.
I guess it depends on what you mean by “that bad”. It has certainly gotten a lot better, nobody is denying that.