Okay, after removing all the preinstalled media players and reinstalling them through Flathub
Technically it’s not required to uninstall the default applications but obviously you’d still wanna do that to avoid clutter.
Fedora should just preinstall everything as a flathub flatpak.
Even though not Fedora-based but that’s pretty much what I have on SteamOS: Firefox, VLC, etc. all from Flathub. Because of the 32bit dependencies, Flathub is my preferred way to install Steam on regular Linux distributions anyway (for obvious reasons not on SteamOS).