I am honestly enjoying playing the 'normal' person of the bunch... and, as others have already said, these aren't normal companions but playable characters that have been designed with personal quests and so that you can experience something new from their perspective when playing as them as your origin characters.
Also, playing with a group of 'superheroes/supervillains' is very common in tabletop rpgs in general, when those that sit around the table and the GM agree to entwine their crazy elaborare backstories into the narrative which is an approach that I enjoy.
By looking at the companions, I can almost imagine the type of player that would create them and I personally find that quite charming.
Ah yes... I am about to have my first DnD session ever (and I am starting as DM, no less) and my players REALLY cut out my work for me.
I have a thiefling warlock (with her own homebrewed devil patron and her own cult dedicated to said devil) as my most normal individual. An aasimar rogue that is (unknowingly) directly related to Ashmedai while being a servant of the Raven Queen, a half-orc blood hunter and a tabaxi cleric.
I was using Forgotten Realms as my chosen world, so needless to say... I been doing *A LOT* of homebrewing so that my player can play the characters they wanna play.
I also had to go from them meeting up in a regular tavern to have them being on a exotic slave boat (because how else would I fit all of these special creatures at the same place at the same time? XD). It is challenging to say the least - but hey, as long as my players are having fun. I sure will when voicing all of the NPCs looking at their group of freaks roaming town.
And I thought my first session would be easy since everybody apparently just "make themselves into an RPG character" on their first session.. WELL, NOT MY GROUP - that's for sure! X'D
... On the bright side - this experience makes the BG3 companionship seem a lot less weird."Vampire spawn? Pfff, try being an aasimar in a universe where they don't even exist. The lover of a goddess? Hah, I am the chosen of my own personal Devil and have an entire cult kneeling at my feet."