Greetings!
Hmmm. It seems that some people for the sake of argument like to argue from the absurd. Of course non-relevant supplies, how often you get a headache, how many bow strings you have, etc, I mean, come on. The essentials are tracked because they are worthwhile and meaningful, and can potentially have an impact on player choices and decisions. So, supplies of rations, water, arrows, flasks of oil--all of these things have a relevant impact not only on the capabilities of the individual, but also have an impact on the group functioning successfully as a team.
If players run out of rations, they need to spend time, effort, and resources hunting animals. That right there is an opportunity. On the other hand, if the players ensure they are well-stocked on rations, then they don't have to spend time, effort, and resources on hunting--they can devote such time, effort and resources towards something else, like exploring further into the Necromancer's Tower, or whatever.
Same thing with arrows. If your Ranger player runs out of arrows, the group loses a considerable source of firepower and tactical flexibility. In addition, if the Fighter or Barbarian also run out of arrows, the group can then be at a serious and even fatal disadvantage, depending on the terrain they are in and the likely opposition. Thus, not stocking up enough on arrows requires the group to cease their immediate operations, and make a return trip to the nearby town for additional restock of arrows and such. Again, why is this such a bad thing? In groups back in the day--to right now--being forced to make return trips into town for supplies is *EXCELLENT* It provides the group opportunities to roleplay more with each other, interact with group NPC's, gather information in the town or along the road, learn more knowledge, and so on. Again, all good things. In addition, being forced to actually attend to such details increases *IMMERSION* and makes the gameplay more real and meaningful, and less like a video game.
In video games, many such details are glossed over and done away with. RPG's and D&D in articular are not video games. So, embrace the details, and enjoy playing the game, and *being* a character in a fantastic world!
Semper Fidelis,
SHARK