Honestly, I think resource management adds an interesting dimension to the game. We are in a "living world", we should act as one.
Both as player and DM, I always keep track of ammunition and food. Never really thought about water, so, that's a 3rd thing to track! ^^
But what's the point of tracking food and water?
One of Grimtooth's Traps is a simple plain old 10-foot-by-10-foot-by-10-foot pit trap ... seven feet deep in Cool Whip.EDIT: If you are being pursued across a dessert you have other problems to worry about.
Whats the point of having a setting at all and not only a string of 20ft rooms with orcs and chests in them? If you want to play a murderhobo hack&slash game then yes there is no sense in tracking water (or anything at all). But in a setting that is supposed to feel alive things like this are essential. Suddenly instead of 4-6 murderhobos vanishing into a dungeon for a week and then reemerging with more gold than what they could realistically carry the adventurers now have to set up a base camp where they can store the supplies they need when they expect to stay longer in the dungeon. The camp has to be guarded so enter the hirelings. But not only do they want to get paid, they also need more supplies, so you likely need to get a cart and pack animals to carry them (which has the advantage that they can help you to carry the loot back)
One of Grimtooth's Traps is a simple plain old 10-foot-by-10-foot-by-10-foot pit trap ... seven feet deep in Cool Whip.
(You can't swim in the stuff, you are too dense.)
The only thing I find more fun that water management is simulating waste elimination.
I mean what do you do with all that fecal matter? Does everyone carry a shovel?
Something I've found helpful when this sort of thing happens is asking the DM to set the stakes up front.
"Hey, I want to hunt for us all. What type of DC would I need?"
On the other hand, Outlander doesn't even require a roll, so your DM really doesn't get it. Is he the sort where a gentle reminder would be useful?
(putting my serious hat back on)
But what's the point of tracking food and water?
Whats the point of having a setting at all and not only a string of 20ft rooms with orcs and chests in them? If you want to play a murderhobo hack&slash game then yes there is no sense in tracking water (or anything at all). But in a setting that is supposed to feel alive things like this are essential. Suddenly instead of 4-6 murderhobos vanishing into a dungeon for a week and then reemerging with more gold than what they could realistically carry the adventurers now have to set up a base camp where they can store the supplies they need when they expect to stay longer in the dungeon. The camp has to be guarded so enter the hirelings. But not only do they want to get paid, they also need more supplies, so you likely need to get a cart and pack animals to carry them (which has the advantage that they can help you to carry the loot back)

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.