Complexity is to make the job interesting or engaging, but the issue we've had since Heavensward is that jobs eventually got too complex to the point that even the newer players had a little struggle here and there on the casual end with certain jobs(namely the jobs that had high APM). Positionals are there to add flavor to the job; and sure, there are arguments out there saying that positionals are detrimental in some fights, but True North's CD is not that long for Melee now compared to back then since it got knocked down to a flat 45s CD with 2 uses to combat this argument with skill level.
As for jobs with more inputs, MCH would like a word with you. MCH still is near SAM in regards to damage, but as Hyomin said the rDPS on top of both MNK and DRG's superior pDPS is allowing them to top without question and create this inane gap we have currently between the top end and bottom end; namely in the 50th percentile. On top of that, they weren't using RDM as an excuse; they were stating how the simplicity of RDM would not allow it to see the light of day in Savage if complexity was a metric they used.
Well, I would want to argue after they lifted the slow-down on Riddle of Fire it's gotten pretty out of hand for MNK in general since it's basically like throwing MNK Raging Strikes for free. People wanted to go faster, so SE listened and lifted it; but I don't think they checked the repercussions of doing so given DRG was already at the top of the heap pre-5.05. If anything, true balance lies at what jobs bring to a raid; whether it be buffs, a damage increase, whatever it takes to get their job done and help the group. Some of these jobs are outliers in this regard since they have one or both things listed:
1) The most damage potential in a given fight.
2) Powerful buffs to "necessitate" their presence in a static group
In this regard, I'm talking about Dragoon mainly. MNK can be composition dependent because of Brotherhood, but running 3 Melee is already an arduous task; hence why people look to BLM's dominance over both the Ranged and Caster Slots due to their substantial DPS output to fill the gaps.
Dragoon in general has been a crutch for statics to lean on ever since inception due to both the damage they do and the rDPS they provide through both Dragon Sight and Battle Litany. Even if they do provide small gains in rDPS, their pDPS was buffed this expansion to make up for the loss of Piercing Resistance Down. The only thing I believe is that they overtuned it pre-5.05 and probably will adjust their numbers in 5.1, but it seems their focus is more on NIN/SAM/SMN due to how both NIN/SMN play and SAM's Shoha being nigh useless on 100% uptime fights for a capstone ability.