It's not like people are asking for Moons or Steelpence or Brass toals.
Well I am, so there. As summed up by Messrs. Blackheifer & Jericho:
As long as they're nice confusing multiples; pounds, shillings, pence type of thing rather than this newfangled decimalised malarky.
"Now, to take the fairy cost a nickel, and in those days nickels had pictures of bumblebees on them 'give me five bees for a quarter you'd say! Now where were we? Oh yeah, the important thing was I had an Onion on my belt...which was the style at the time!"
-Abe Simpson
I don't believe the U.S. ever had anything close to as complicated as pre-metric currency in Britain, not to mention anything remotely as confusing as using L to mean Pounds, and d to mean pence. Ha'penny, Penny, Thruppenny bit, Sixpence, Shilling, Two-bob, Guinea, Half a crown, Crown, Half Sovereign and a Sovereign, if that confuses you imagine how confusing BG3 would be if it adopted a similar system for multiple currencies.
ISTR the LSD thing is explained not so much by the psychoactive substance (though it may seem that way) but libra, sommat*, denari.
* not quite accurate but I can't remember offhand and I'm too lazy to look it up.
Edit: I'm also old enough to have used proper money before they introduced that nasty cheap new stuff in the early '70s but I don't remember a lot about it. I mean I can't remember what I was doing this morning never mind 50 years ago.