The HL3 memes don't even seem fair to use anymore. I don't even want to un-seriously make joke fun of them at this point. They are just genuinely doing so much for the community.
Targeting Wine/Proton is the best of both worlds for everyone. Developers need to Just™ not use a few footguns that they mostly don't have reasons to touch anyway, and otherwise they don't need to change anything, while consumers get a game on that works just as well on Linux as on Windows.
If you don't do anything weird, you land in that 80% and everything works as it should. With developers noticing SteamOS being a thing, more of them start doing sanity checks to make sure it works on Linux, and that 80% starts growing to 90%.
Then there's the kernel anti-cheat that's unfixable though, which pulls the percentage down again.