Seeing as how BG3 is really leaning into the RP aspects of D&D, I can't help but feel limited in our current selection of armors/outfits and weapons.
Particularly in regards to outfits - right now all outfits are armor. I think there are certain benefits RP wise you get from certain classes that don't need armor or obvious weapons because they don't necessarily look or feel like an adventurer.
Examples - A bard might be able to use armor, but maybe they prefer mage armor because it makes it easier to flirt with Raphael in an attempt to get his guard down, or maybe they can deceive a merchant by pretending they are just a victim of this situation with no survival skills. Sorcerers get the metamagic "subtle spell" which not only lets them cast in silence, but allows them to cast a spell in a conversation or other situation without being noticed. Barbarians look tough, but they don't wear armor so maybe it makes it more likely that an enemy will try to go for them than Wyll, wearing his medium armor.
Anyway, point being, there are a number of situations where I feel like not having armor, and being able to use different normal outfits could increase the immersive feel.
Armor feels very... dull, for the most part. Why is our ragtag group ending up with a lot of the exact same looking armor they looted off corpses from different areas, groups, races (I don't mind not having armor require different sizes for small races, because it could be very annoying, but it isn't the most immersive thing). Even just a few more models for each would be really nice.
I don't care that much about different looking or types of weapons myself, but I know there are people out there, some of whom I know, who can enjoy a game just because of weapon look variety. I don't think BG3 is the right game to worry about hardcore weapon customization, but having some slightly different styles of the most common weapons would probably improve some people's enjoyment more than expected.