From Fedora Project Wiki
We used to have a yum plugin that did something to make sure that lang packs are installed when needed:
https://fedoraproject.org/wiki/Features/YumLangpackPlugin
It appears that at some point dnf support for this was planned. At least yum2dnf(8) lists a dnf-langpacks package. But it does not exist.
Problems:
- 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