DNF supports automatic installation of langpacks for the user's current locale since Fedora 24 using RPM Weak Dependencies.
- not all langpack subpackages are present on install media
- we don't have a list of 'interesting languages'
- gnome-software does not install languages packs automatically
- gnome-software does only install the current language when installing flatpaks
- when changing languages in the region panel, no lang packs are installed
- gnome-initial-setup does not install lang packs