I seriously don't understand how people think class difficulty has and even should effect damage numbers.
I get that having a lot to do to just do the same amount of DPS feels bad sometimes, but the classes should probably be better investigated by SE so they all have their neuances. What's difficult for one person might not be for another, Pure apm isnt an indicator of difficulty either.

Also as far as ive seen ninja and summoner are the hardest to play right now and get absolutely nothing from it.
Also some people say black mage is the most difficult and therefore best damage. But black mage being difficult comes from older HW mentality when the timing on AF was hella strict. Now BLM really isnt that hard at all to understand. just like every class the nuances are there but compared to before it's much less punishing to play.