“Note: I don’t recommend installing the Flatpak version of Steam. It has some issues specific to Flatpak, and makes your Steam files difficult to reach which can be annoying. Use your package manager instead.”
What issues? I’ve been usin the Flatpak for more than a year without issues, both on Silverblue and on Arch. On the other side I had games not running with the version on the repos with Arch and Nobara.
And difficult to reach files how? Just add a shortcut on Files or Dolphin to the Steam folder for easy navigation.
Edit: saying not to use the Flatpak version is like saying not to use the Steam runtime.