Quite. If the scenario creates a specific resource issue like being lost in the desert, then resource tracking matters. But if you are in a normal situation there is no need.
I'm not that concerned if they're in a situation where resupply is relatively easy; I just get them to dock a bit of cash and carry on.
But inability to resupply often comes up more often and more quickly than you might think. A typical dungeon doesn't provide much by way of fletching materials thus managing the supply of arrows (and worse, crossbow bolts!) becomes a very necessary task. Looting fallen foes of any ammo they might have becomes vital.
This is what makes sling so useful - it's very rare that you can't find abundant ammo for it.
You're right, though, in that oftentimes these things don't matter.......until the situation arises when they suddenly do matter and the players need to know exactly what their PCs have on hand. If things are well-tracked as SOP this isn't an issue; they have what they have, no arguments, carry on. But if they're not well-tracked and it suddenly becomes an issue you're now open to all sorts of needless arguments.
Happened in my game a while back. 6th-7th-ish level party are in a typical dungeon, they enter an area and their magic stops functioning - which includes all their light sources. At the time they didn't have anyone who could see in the dark indoors (I use 1e-style night vision rules) so what followed was a frantic flurry of character sheet flipping as they searched for torches.
There wasn't a single torch or lantern in the party! They had become so reliant on magical light sources they'd all failed to bring mundane lights along; all they had for light were three tallow candles someone had stuffed in their pack, and those didn't last long.
Needless to say, next time they were in town there was a run on torches and lanterns!
The characters know how to live in their natural environment without input from the players.
Some do. Others maybe not so much, depending on the specific character(s). Can't make a blanket statement like this.