DNC is the poster child of 'the devs didn't talk to each other' it feels like. In this expansion, we got a system that allows actions that are 'only useable after X other action' to replace one another on the hotbars to consolidate buttons a bit (eg, HighJump > Mirage Dive, or Ikishoten > Zanshin). We also got certain actions that grant gauge changed to grant a buff that allows a free cast of the gauge spender, to reduce overcap issues (eg Hypercharged on MCH, Ideal Host on RPR).
But on DNC:
Technical Step turns into Tillana, you can't separate the two
Tillana grants 50 gauge, during Tech Step when you're already drowning in gauge, and so it's super easy to generate 50 gauge and overcap within the 2 GCDs (spending gauge to get low, waiting for that GCD, then pressing Tillana and waiting for that GCD). Also, the ONLY thing that Esprit can be spent on is Saber Dance, so the excuse that'd apply to something like NIN (where you can choose to spend on Bhav, Frog or Bunshin) doesn't work here
Fan Dance 4 can only be used after Flourish, you cannot combine the two
Starfall Dance can only be used after Devilment, you cannot combine the two
Last Dance can only be used after Standard Step/Finishing Move, you cannot combine the two
Closed Position is still jank as hell to swap from one player to another (requiring a press to 'deactivate it' and then another to place on someone else), I wish it worked like Kardia (instant transfer, 5s CD)
But the biggest crime for DNC in my opinion is with Finishing Move. I get that they wanted to make it so your second Standard Step fits into the burst window easier, but this move removes 40% of the DANCING, from DANCER. You go from 4 Standard Steps and a Tech Step per 2mins, to just two Standard Steps and a Tech Step. Who asked for the Dancer to do Dance Steps less often? That's the thing that sets them apart from other jobs in terms of gameplay! It'd be like if NIN got a change that means 'press Kassatsu, it turns into Hyosho, press again to instantly use Hyosho at the cost of one Mudra Charge'. You'd be pressing Ninjutsu less, that detracts from the aesthetic/identity of the job
'Render Hammer' doesn't replace 'paint Hammer onto your gauge, when tf am I going to paint another hammer without rendering the one I currently have on my gauge first?
Same could be said of Mog of the Ages replacing Creature Motif but there might be some wild opti I'm not aware of for that one
Comet doesn't replace Holy when you're in Subractive Spectrum, but you cannot use Holy while in Subtractive so why have the option there and greyed out?
Same applies for Fire/Aero/Water > Stone/Ice/Thunder, if I can't use FAW while in Subtractive why can't I just combine the two buttons?
Star Prism can only be used after Starry Muse, but the two cannot be combined. At least with Rainbow Drip you can hardcast it so there's a reason for it to be separate
I'm guessing the reason here is, if they combined some of the stuff that would make sense to combine on PCT, the job would have like 12 buttons (and another like 8 for role actions/sprint/potion/LB) and people would point at it and laugh and say 'haha look at the dumbo job with so few buttons'