It might be somewhat controversial of a take, but to me an awesome-performing Proton version of a game is far better than a Linux version that may be native, but has severe deficiencies and/or lags behind its Windows version.

To me, my favorite native Linux games would be ones that do things on Linux that are not possible on other platforms. Generally, this would be an "unfair" advantage, as games should strive for feature parity on all platforms within reason, but so often we end up being on the wrong side of that equation that seeing some of the perks of the platform is nice.

To my knowledge, the only major game I can think of that does this to a certain extent is Factorio, which enables non-blocking game saves on Linux and macOS and not Windows. It's not a Linux-exclusive feature, but it's nice that the developers went through the effort to implement the feature on Linux even though it's not possible on Windows.