I agree wholeheartedly with the initial premise. However, I feel it's worth pointing out that content like Normal Raids aren't a great place to draw from when trying to assess job balance (no enrage pressure/randomized comps/players often don't take it particularly seriously) and that Machinists are still under-tuned even given the buff/non-buff job dichotomy.
Dancers, for instance, should have higher rDPS variance than Machinist and be capable of a higher potential damage contribution as a result. When you pull Savage clear data from the last two weeks, however, you'll notice that it's not just the upper potential that's higher:
https://i.imgur.com/SudD4Ay.png
MCH & DNC Abyssos (Savage) rDPS Standings: Sep. 1, 2022 - Sep. 15, 2022
As it stands a competent Dancer in this context will out-perform a similarly competent Machinist at all skill levels. If you want to balance around buffs providing rDPS variance, then Machinist should have a higher median rDPS contribution than Dancer while still losing out to Dancers and Bards at the upper percentiles (which is actually how they used to compare to one-another during Shadowbringers).
This last bit is spit-balling, but I think part of this is that in addition to Machinist having slightly undertuned potency values, the 2-minute standardization pass the job team implemented with Endwalker made buff coordination easier and more impactful. In-turn this boosted the performance of the median player on said buff-centric jobs.
