To be honest I deeply despised ammo management in BG2 due to the amount of clicks it generated while posing no challenge. Like you could have easily couple thousand arrows if it pleased you. Easily.
Rather than restoring the ammo system I would say the ressource management system as a whole needs way more love but that really doesn't come without major re-design of certain concepts like endless fast travel making any system of this kind straight up pointless.
My best proposals regarding this particular aspect:
1) Separated maps/zones( like grymforge for instance!) where you know in advance your ressources will be limited and you will not have the ability to reach to your endless bag of goodies could be one way to adress this( giving devs control over player's ressources, the player party has only what's in their pockets at a given time).
From player's perspective he receives the info he won't be able to rest too much in the given area he's going to and worst case scenario , if he thinks he can't complete all encounters he will be able to leave. But he won't be able to return.
The logic behind it:
In a more controlled environment choosing when to rest and engage combat suddenly becomes a real issue if failure due to ressource exhaustion linked to planning failure on player's part is an actual possibility in a given scenario. Grymforge is quite large but let's say you cut off the boss /lava area(just to illustrate my example, i'm not saying grymforge should be shrinked lol).
The player receives the option to leave the area( but he can't come back at all).
He can long rest once.
Short rest twice.
Consumables suddenly get an insane value in such a situation.
We don't introduce ammo management so poor virion doesn't throw his keyboard throught the window. Win win!
Such areas could have quests linked to them( small quests) involving some kind of investigation to discover what awaits you, what type of enemies you will face, what challenges(Maybe it's a very montainous or dark region?).
Maybe what kind of equipment you would need for this particular zone?( Like a grapplin hook or something, just a quest item you could obtain/buy as part of the " preparation quest" while on site having this quest item could open a new passage. --> I'm giving this example because it sounds insanely cringe in the light of BG3 verticality , right? Well in this context we have no idea where we are going whatsoever. We don't know if we can afford using our spellslots to jump around like rabbits.
Imposing all those restrictions and preparations on a player makes little sense on the scale of the entire game. But in the context of 1-2 special areas ? I think it can be very cool.
2) Essentially all larger areas could be seperated by a larger distance this way making the druid grove a hub ( with endless storage) while the " travelling " setup would indeed limit your inventory space, sleep count, what you take away with you etc. Below it's just me talking about random stuff cause it makes non sense in BG3 whatsoever in the form i described it.
Bah, you could even go crazy with it and make travelling an actual challenge with food rations in the early game limiting your effective travel range while introducing the concept of caravans to not make it a hassle in the mid game and this way reduce the amount of resupply runs required( while coming back to ressuply etc can be fun once or twice if it happens too often it will be insanely annoying too).
Depending on your allegiance with certain factions some areas of the " travel map" could be more or less dangerous etc maybe with some random encounters but we're talking about a different game here. Like literally, BG3 with it's concept of a no -loading screens at all and fast travel simply can't afford to go crazy with this because that entire concept assumes portals either don't exist or are heavy limited.
Solasta attempted to adress that issue by having travel time+random encounters+ portals at key places. It worked ok -ish , wasn't too crazy either. Like I wouldn't trade BG3 for Solasta over that system, that's my point.
So there are ways to make that aspect of the game interesting and enjoyable without feeling like someone forced it onto BG3. But yes, any ressource management system is bound to fail in an open environment with infinite fast travel , endless pockets and ( admitedly?) infinite sleep.
