Ranged DPS, choose a weakness that would justify a buff

[Lastelli]

the notion that the evil evil parsing side is off by more than 500 dps, like off by enough more that groups simply realize this other class is better is one i will sincerely doubt.

Realistically the answer will be more in the realm of: "people just like to use what they know", yes people are like that. if not that than maybe they are right, dnc is stronger than mch at 99,5+ percentiles and therefore better for speedruns, especially as due to proccs alone dancer is a class with more volatile damage numbers than mch. in a normal group if the dancer is allways 300 under the mch unless its his god run than you will say fuck that, dnc sucks. if you are doing 30 runs in a row just hoping for the one best run ever that changes completly, at that point you may aswell say "whatever, everyone else just play perfectly, we try till our dancer has his god run".

However, even if performance on dancer was as consistent as it is on mch, which it is not, its still a fucked up thing to make a class effectivly suck for 99% of the playerbase so the top 1% doesn't "abuse" it, mind you the top 1% of raiders, not of all players. speedrunners going for top spots are a ridiculisly small sub group and there will allways be a "best" class, balancing around that is like draining the ocean while trying to get 2 perfectly equal cups of water, its futile AND stupid.

That's part of the deal. Higher variance means higher risk. Your payoff for that higher risk is higher potential damage at higher percentiles. Making DNC as good as MCH in an average run would just kill MCH in all possible scenarios. DNC being lower than MCH at lower percentiles is a necessity dictated by its own design. At least now MCH is good in a prog/unoptimized setting...and this is the only case where it's marginally better than the other two.
Also, you're ignoring the specificities of the 3 jobs. Among the 3 ranged dps, DNC benefits greatly from downtime, unlike MCH and BRD. BRD, on the other hand, becomes absurdly powerful in a multi-target scenario, which is pretty good for DNC as well thanks to standard/tech finish and saber dance (MCH struggles in this case). Just because savage doesn't usually show these peculiarities, it doesn't mean they aren't there (look at ultimate data, for instance). If you want to homogenize single target damage for the 3 ranged, the first step is to make sure to remove these scenarios where one has a clear advantage over the others.

Anyway, give it a little time and you'll see DNC reaching MCH level of rdps on fflogs soon enough.