Why are low standards for dps acceptable?

[Thunda_Cat_SMASH]

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This is the "holy trinity" concept in its basic form: the tank keeps taking and mitigating the incoming damage in order to allow the DPS to kill the enemies as fast as possible, while the healer keeps the tank (and the DPS, but mostly the tank) alive.

The problem here is that by design, DPS also have 0 responsibilities outside of cutting edge content. There's no DPS checks tight enough to actually necessitate high DPS, which is why it's very common to see people set up odd parties with one tank and 3 healers, 3 tanks and 1 healer, or even just 4 tanks precisely because DPS are largely irrelevant, even when dealing high damage due to how little time is actually saved by bringing along the 2 DPS.