There's a lot of problems with that "SMN DPS calculation". It assumes that the SMN instantly has up all DOTs, when it takes 15s at minimum to get every DoT up. You also can't cast Fester until at least 7.5 seconds in. The damage calculations also assume that you instantly reapply every DoT as soon as it wears off which, in practice, is nearly impossible to do thanks to latency, staggered durations, etc. So unless you summon your SMN whenever a dot gets close to falling off, you're going to be missing a chunk of that dps.

Also, because pets don't scale with gear, the "100 potency dot" of a pet is actually far lower proportionally once your SMN starts gearing up, meaning that the difference between an item level 90 BRD and SMN will be even greater in favor of the BRD.

Can you clear all content with a competent SMN? Sure, probably. But BRD hits harder and can be played lazier while still getting better results than a skilled SMN.