One may wonder why the average waiting time for a dps has not decreased, but instead even increased, since then. Having economic insight, one may envision the three roles as three choices a dungeoneering player decides on as part of an economic decision, and also that the the three choices, on the large scale with several people, tend to economic equilibrium with each other.
Cost and benefit
When faced with a choice of activities to perform, a person makes an economic decision whenever they try to gain the most satisfaction by choosing the best activity for them. For each activity, they need to compare the costs incurred with the benefits gained. The excess of the benefit over the cost is their (accounting) profit from the activity:
Accounting profit = Benefits - Costs
