There are plenty of impactful decisions in BG3 fights, like what to spell to concentrate on, which targets to prioritize, etc.
Really ? What food am I going to eat ? Where am I going to go for the high ground advantage ? How am I going to jump to avoid this AOO ?
Put it this way - these decisions actually let you win the fight. Checking your arrow count doesn't win you the fight, it just postpones the fight for X irl minutes until you get more arrows.
Or maybe you'll just have to change your strategy until you find arrows on dead bodies
Like I said before, in both melee and ranged weapons, damage is inherent in the weapon - normal ammunition does not impact damage. Your method would force strategic and economic usage on ranged that do not exist on melee (special arrows which DO convey additional damage are in fact limited, by both availability and cost). If you want to force arrow economy strategically onto ranged, then I propose as an equivalent, you impose that old "favorite", weapon and armor breakage, and mandatory weapon and armor maintenance with rare and expensive oil and rags - couldn't clean your weapon after battle? Oops. Now it's broken and you get to fight bare-fisted, just like the archer who is out of arrows. Hell, let's toss in random body conditions too - that dinner you ate last night was "bad" and now you get to fight with diarrhea - -3 to attack and defense rolls!!