In the ideal situation, you'd be able to pick starting equipment and under that, a selection for picking casual clothes
This allready isnt "ideal" for me ...
Personaly i hated this nonsence in Dragon Age: Inquisition ...
Especialy since i found no way to change what my character is wearing until i get to skyhold.
And ESPECIALY Especialy since my main character was a Qunari Mage ... who was by system forced to change her "uncomfortable" loose airy robe ... for some stupid ugly tight pants and leather jacket. O_o
Sory not sory, it was just ridiculous.
I have no problem with casual clothing existence per se, but i see no reason for them to be another part of our equipment ...
Imho, casual clothing works just fine as regular pants and shirt items in your inventory ... actualy, just one item, since unless i remember incorectly BG-3 dont have separate pants slot ...
Something like: You want to change? Change.
But i certainly agree on that there should be MUCH more regular clothing findable, lootable and purchaseable ...
If for no other reason, then for Wizards who preffer regular pants and shirt over, how people around here call it, fancy bathrobe.

all the variants they've already made for the game...
This may be second problem tho ... i dont really think they made any to be honest.
Dont get me wrong, yes i noticed that some races have different underwear. But i believe that is just part of their model body.
Like, when they get undressed for romance scene, that involves sex ... they dont "unequip" their underwear, they litteraly swap body for naked one.

You can think about it as ... permanent bodypaint!