Gold doesn't really make sense in any fantasy games.
I have to admit that the fantasy capitalism in BG3 so far has been quite unsatisfying since two of the shops that I've come across in my first play fucked off semi-unexpectedly before I could afford anything they had to sell... I'm not really sure how much of an impact charisma has on bartering but not much.
Generally the process of looting, tidying your inventory, assigning to your hotbar is a tedious mess at the moment. It needs a lot of polish. I get the sense that there are some items in the game which are meant to be useful but aren't yet... like rope, and empty bottles. At the moment the shop is necessary as a means to de-clutter your inventories. It's kind of annoying to go from having no money to buy the things you need, to, after completing one particular quest, having lots of money and no shops to buy them in.
It's a quibble really... I'm sure there are plenty of shops in acts 2&3.
