If you use Flatpak keep in mind that Flatpak lets old versions of a package just… lay around.
This eventually will cause problems, especially if you have say an nvidia card. It all works fine as long as there are gradual updates of the same version such as Nvidia 450 driver. But when you switch to the 455 driver Flatpak just leaves the latest 450 driver laying around. And nvidia drivers are rather large. I have seen people asking in Linux forums because their / partition is suddenly full, and realizing they have over two gig of NVIDIA drivers laying around.
To solve this, use the “uninstall --unused” option. Or, more efficiently, do like this:
flatpak update && flatpak uninstall --unused