Limiting ammo is tedious in PnP and in video games. BG3 is not a survival game, so why bother.
BG1/2, Solasta, Wasteland, XCOM,... aren't survival games...
My point is that if it isn't a core mechanic then why bother. I think that you should either have every arrow count (survival/horror) or not keep track.
If I can just craft/buy arrows then all that means is that I need to remember to talk to a vendor/craft every so often, which is tedious at best.
Hell, even Elder Scrolls game have limited ammo and I can't remember a time I ever ran out of them in those games.