Competition serves as a natural regulation.

The co-evolving set of competitors hold each other in check.

Competition sets co-evolving constraints that are balanced and just right to encourage a gradient of improvement that pushes all competitors to excel.

But it's a bowl on a pedestal kind of dynamic; within the middle range the competition is self-balancing, but if you get out of the place where it's possible for competitors to catch up, the engine that leads to quality growth leads instead to run-away power accretion.

By using the power-accretion gradient and aligning with quality improvement, everyone improves due to individuals' greed.

But greed without the constraints from effective competition consumes everything.

It is only the competition, the dynamic equilibrium, that drives to quality creation, the positive-sumness of greed.

Without competition, greed just consumes all and puts everything into a fully captured heat death kind of static equilibrium.