I've played in PnP games where we track ammo and games where we don't. I understand the rationale behind it, but unless you're playing a wilderness survival game where resources are scarce, it mostly just feels tedious.

People don't tend to bother with things like sharpening and oiling swords or repairing armor in the game - we just assume that characters know how to maintain their gear and abstract away the boring part. I feel like ensuring that you have enough ammo for ranged weapons falls into that category unless there is something about getting enough ammo that is supposed to be a challenge.

From what we've seen of BG3 (especially with the portals), it doesn't seem like getting your hands on ammo would be even remotely difficult.