Real world poverty is a pretty big discussion that probably doesn't belong on this thread.

Back to the topic at hand, queues are better discussed using more basic economic concepts of supply and demand. Supply of DPS in 4-man content currently exceeds demand. Economics dictates one of two things will happen:
A. Price decreases until market reaches equilibrium.
B. Excess supply creates a surplus of unsold units.

Since FF14 doesn't really have mechanisms equivalent to "price" in economics, that leaves outcome B as the only result. This means DPS waiting in queue. The wasted time in queue is akin to surplus product going unsold in economics.

"Supply" is how many players queue into a specific role. Supply is determined by the players' choices. It is possible to influence supply with incentives, game design, classes made available to players (anyone remember DPS queues going to heck when Ninja was introduced?). The supply side is tricky to change and it is where most efforts have been focused.

"Demand" is an interaction between the Supply of all three Roles. On the one hand, demand for each role is based on supply of the other two roles. On the other hand, the formula for that interaction is set by the Devs: 1 Tank = 1 Healer = 2 DPS. If the devs were to change the formula to 3 DPS, they would be increasing the demand for DPS.

You can argue that it's not feasible to change the 4-man composition to a 5-man or that the current setup is better, but to say that it wouldn't make any difference on queue times is simply not correct.