In the original games your non-magical weapons could break.
That was in BG1, due to story reasons. The mine you are sent to investigate as your first mission in the game is producing bad metal, and it is explained that the weapons made from it are prone to breaking. That is very early on, and after you succeed, weapons will not break anymore.
Besides, the way to work around this was:
immediately converge to "buy enough arrows so you never have to worry about running out."
which is exactly what I foresee if any ammo is implemented. Nobody is going to put 30 arrows on their ranger and go adventuring. It'll be more like 30.000, which is why I'd claim, that we can leave this out entirely and it will not disturb the flow of the game, which will in turn make it feel better. I very distinctly recall how annoyed I was in the earlier Baldur's gate games, because there the arrows didn't refill the quiver automatically, and the amount of arrows that would fit in there was enfuriatingly small, so it would happen quite regularly that the character runs out of ammo and switches into melee, you notice it too late and they get torn up, petrified, level drained and what not. I can't say that this mechanic added any fun to my experience, and I don't think it will do so for BG3 either.
UNLESS Larian has plans for a really sick prison section where you have to fight your way out with the equipment you find along the way, and it is so hardcore that you have to ration the amount of arrows that you are going to spend in a fight, in THAT instance sure, there ammo has a place. Which they could code it so you only require ammo for this section, so it would still be possible with how we handle it now. Other than that, we all know we're going to stock up 30.000 arrows when we leave town, so let's just forget about it.
With warm regards
-Thunder
