One downside of the Firefox flatpak from Flathub is how it doesn’t support screen sharing in video conferences by default (unless that has changed in the latest version).
You can do an override to make it work though, and it’s pretty easy to do with Flatseal. Check out Screensharing problems in the Firefox flatpak after upgrade to Fedora Silverblue 34 - #4 by johnrory.odwyer
Hopefully this will be fixed at some point in the near future.