@NaN
Ok, I edited the Steam-native application and I found that it runs /usr/bin/steam-native. I expected that it runs the script in /usr/share/applications/ so-called steam-native.desktop. I don't have any steam-runtime.desktop in that directory. It would be nice of you if you could share your file here so I can have it and add it to my system.
It is also strange that steam-native runs when even I run the command steam-runtime in the terminal.
I search the internet for the garuda's provatebin and I found this. Unfortunately, the site seems to be unavailable. If it is ok I can post the content of steam-native.desktop here.