I'd argue that "native" is much more of a state of mind than a clear delineation anyways.
Among many game developer studios, the Steamdeck is increasingly becoming the defacto low-spec hardware target. Running their game on a Steamdeck becomes a core part of the QA process, because there's a few million Steamdecks out there actively playing games, and if your game runs on a Steamdeck you basically know it'll also run on a very wide range of hardware configs.
So while the game might be targeting a different API than the standard ones exposed on Linux machines, a lot of games now are directly designing their software to make sure they run well on a Linux handheld. Meanwhile, Linux is adopting more and more features to better support this non-standard API set.
At a certain point I think we can just call Proton/WINE a 'native' API for gaming on Linux, and say that games developed with Proton/WINE in mind are native games.
Perhaps we're not at that point yet, but we might be there soon.
Among many game developer studios, the Steamdeck is increasingly becoming the defacto low-spec hardware target. Running their game on a Steamdeck becomes a core part of the QA process, because there's a few million Steamdecks out there actively playing games, and if your game runs on a Steamdeck you basically know it'll also run on a very wide range of hardware configs.
So while the game might be targeting a different API than the standard ones exposed on Linux machines, a lot of games now are directly designing their software to make sure they run well on a Linux handheld. Meanwhile, Linux is adopting more and more features to better support this non-standard API set.
At a certain point I think we can just call Proton/WINE a 'native' API for gaming on Linux, and say that games developed with Proton/WINE in mind are native games.
Perhaps we're not at that point yet, but we might be there soon.