Gnome Software shows two repository sources for many Gnome core apps, one is for the Flatpak version and the other one is for the RPM version, as seen below:
However, the RPM version is still the default installed.
Why the Flatpak version is not the one installed by default?
IIUC the flatpak is designed to work on almost any machine and installs its own environment for running. Thus many things, libraries included, are installed in that environment and the flatpak is considerably larger than the parent rpm on which it is based. This enables a flatpak designed for a library that is possibly way older or newer than installed in the OS to work regardless.
You may have one flatpak installed that was built for fedora 34 while another may be built for fedora 36. The extra space and environments are usually not needed for apps that are available with an rpm for direct install but with certain OSes (like silverblue) it may be the better choice.
The default repos are focused on the rpm versions of each app.
The complexities and additional space and environments needed for flatpaks also add to the maintenance of the packages and would interfere with the rapid development process of fedora.
That’s probably a better topic for https://discussion.fedoraproject.org. Flatpak and RPM are both supported by Fedora and as such are supported here. The other site is a better place for discussions about packaged default ideals, IMO.
My best guess is that this package was part of the base installation for Fedora Workstation and the installation images are based on RPM, so it was initially installed through Anaconda (or dnf) instead of through Gnome Software.