It has never been a “legal headache”, more of a bit of additional work for distro maintainers (to keep codecs separate from the rest of the distro) and a tiny inconvenience for users (they had to click an additional button after installing the distro).

Was that ever? Whenever someone whined about codecs back in the day, I would just install mpv or vlc (which were and are in most official distro repos I know of) and call it a day.