This is sourced from 3rd-party metadata providers and not editable (in Roon) by users.
Some info about metadata providers used by Roon:
What seems to be missing there is musicbrainz.org which should be editable by everyone interested (but I don’t know if artist bio is also sourced from there):
“MusicBrainz is an open music encyclopedia that collects music metadata and makes it available to the public.”
If you wish, you can also add your vote to existing feature suggestions: