There's a certain value put on having something that less aren't able to necessarily achieve. The reason that we have achievements/trophies in game, what puts value to high end game gear (aside from its special perks), ...life. People strive to achieve (well, they should anyway) and improve themselves,, and part of the value is that while this person has, this person may not. Now, I'm all about helping others get there and through things, but at the same time, if the entire player base had it, since this is something akin to an MMO, then it becomes devalued. If everyone has MIDA, the gun just gets an eye roll, if everyone has a Tracer skin, we use a different one, etc. We don't want everyone to drive the same car, or wear the same shirt... I also believe this is partly why we have no trade system, to keep that value and have a reason to go get it. Ammo is a miniscule addition to the challenge to keep us on our toes, but it's still part of the gameplay dynamic.