I think they should make a fantasy game where everyone has a Texas accent, but not make it country or western themed at all. Just act like that's the perfectly normal way people talk in a generic fantasy world.
Fun fact, the German version of Baldur's Gate 1 "suffered" greatly from not-so professional voice overs which introduced a variety of accents including austrian and swiss accents. Absolutely brilliant! Even though not fully intended. If you speak german and have never tried BG1 like that, give it a shot.
Certainly the most memorable voice over of all video games, for me.
Davaeron just kills it.
Nostalgia aside, that was a bit too much though.
Goblins in BG3 seem to be way more intelligent than in earlier DnD and it is a little off putting, though it could be explained by the absolute insisting on almost-coherrent sentences comming from their mouths.
An accent other than "official" it might be seen as offending, as it probably is.
Common would know more flavor/accents though and this could serve the game well. It's nice to be able to understand all spoken lines easily though, if this is something problematic with accents, nevermind.