Does camouflage matter?

Nature has a long track record of using camouflage to protect species from predators and hide predators from prey until it's too late. Many of use have encountered mimic monsters or at least heard of them. Creatures that, true to their name, mimic items in a dungeon only reveal their nature when a party member gets too close. Other fearsome dungeon dwellers will appear to be normal stalactites only to drop on unexpected adventurers, piercing them through and through and killing them on the spot.

Yet there is more potential to camouflage than just the initial element of surprise. How often is it used to disengage from combat? A strike, displace and strike again strategy would require the party to reacquire their target. Camouflage can help when running away by reducing the distance before visual contact is lost. Camouflage becomes an important element in an encounter when engaging at long distance; be this arrows or magic in a fantasy setting or long range weapons in a modern or futuristic game. You can't shoot a target you can't see. Obviously the players can always do this:

Extremely inefficient in regards to ammo and also has the drawback of giving away your position.

How comfortable would you be if a game depended only on the hiding and spotting roll? Get seen and it's game over. How much would a game change if spotting and camouflage became a central element in an encounter instead of a modifier during the first round's initiative roll? How would this influence your perception of skill and proficiency when such skills work side by side with hit points to keep your character alive?