Screwed up fonts in GTK software, even though the xdg-portal app for KDE is installed. At some point I just gave up. I see no reason to install any Flatpak if the software in question is already in the distro's repository and current enough anyway. Maybe except OBS, because the Flatpak version comes with Youtube integration which, to my understanding, needs to remain closed source and won't make it into a FOSS repository.