I don't think it'll be as bad as it was in DOS2. DOS2 had every race covered by the origins, while BG3 doesn't (along with classes).
If you want to experience the most amount of unique content as a Tav that an origin won't have, you should pick a class and race that isn't covered by any of the origins.
As far as races go, that means Half-Orc, Dwarf, Halfling, Gnome and Dragonborn. (This is actually a far bigger list than I expected, and ties into the other thread about the lack of variety among the companions.)
As far as classes go, that's Bard, Sorcerer and Monk. Paladin and Warlock probably count too, depending on which faction you side with in regards to the Druid grove, since I don't think it'll ever be possible to have a party with Wyll and Minthara together.
