DPS checks vs mechanics

[Judge_Xero]

I think DPS checks are actually good ways to practice rotations if you want to output high damage numbers.

You are exactly right. Just hitting a dummy does not compare at all to fight dynamics. It only means you have a general idea of how your class performs.

Fitting in those clutch moves before getting one shot, efficient add swapping to utilize your greatest pps skills, AOE/resource management CD management for the greatest usage. The list goes on for days and is not something you can learn from simple dummy tests.
These are mechanics in of themselves on different fights that require a different DPS approach to meet these checks on top of anything else in the fight.