Fedora ships incomplete codecs for legal reasons. Other countries still have the same laws but they are not enforced. Those codecs are nonfree, meaning Fedora would need to pay money for every download, making them poor very quickly.
Rpmfusion is hosted in France, where those restrictions are not enforced.
Then there are ublue variants of the Atomic images, which may have some downsides (like no automatic version upgrades, or not using an ostree remote but OCI containers), but they preinstall those codecs.
If you use Flathub Flatpak Firefox and media players (Celluloid or VLC are good), the codecs come from Flathub which also doesnt need to fulfill those legal requirements for some reason.
The only problems where you need local codecs are:
- Thumbnails for nonfree videos in Filemanager
- using binary or Fedora Firefox
- using ffmpeg or other locally installed tools for efficient media manipulation