You have no idea how much extra work it is to maintain a Linux-native version that works predictably across the entire range of Linux machine configurations.

Because in this day and age targeting a billion different configurations is stupid. Steam Linux Runtime exists to remedy exactly that.

Proton is already known to be perfectly capable of running most games as good as or even better than Windows.

And then an update comes along and breaks compatibility. News stories about this are frequent.

instead of having to implement client-side decorations for GNOME users.

• Games usually run full screen.

• SteamOS doesn't use Gnome.

• Native Linux games targeting only Steam Deck's setup are still a better experience than Windows games under Proton aren't integrated with Gnome either because Valve doesn't care about Gnome.