PSA for openSUSE Tumbleweed users wondering why Proton doesn't launch properly on a fresh install

Had to deal with this recently. The cause is openSUSE's move to SELinux on new installs, which by default blocks the required permissions for the RPM version of Steam. You can correct this with these commands: ausearch -c 'steam' --raw | audit2allow -a -M my-steam to create the permissions file and semodule -X 300 -i my-steam.pp to apply it. Hopefully this saves someone else from the wild goose chase I went on earlier.