Mood here. On top of that you have some jobs' primary gearing objective as a result being to absolutely micro manage SkS (as in needing one of the few specific exact GCDs that divide exactly evenly into 120s) so that their big hits land exactly on time.
SAM went from being one of my fave DPS in Stormblood to "ugh I hate this" territory in Shadowbringers and the GCD management (not to mention artificial suboptimal filler based thereupon) for the sake of aligning Tsubame was one of the biggest drivers. Wasn't this whole thing why they got rid of Accuracy, because having to micro manage a specific stat that exactly (unlike the "the more the better" universality of all the other stats) was miserable? (Heck. Even WoW got rid of its multiple flavors of Hit Rating for that reason. When even Blizzard decides something is too unfun ...)
I main DNC these days and I'm not sure if we're supposed to do the same for Tillana or not (to be fair, I'm not sure there's much of anything static about DNC with how many random proc things you have to fire off, other than trying to do your dances on time every cooldown, which combined with how much depends on your dance partner's performance rather than your own makes it perfect for an okay-but-not-great player like myself, lol).
IMO, it seems like optimally, most classes should get the vast majority of their performance relatively easily by simply doing the holy trinity of "obvious button is obvious" "keep your GCD rolling" and "don't clip your GCD by overweaving" and then get a little bit of extra performance wiggle for the "super tryhard" types to show off, although given that serious players usually rank based on percentile competition rather than raw performance, I'm not sure how much it would help the culture at this point, either.
As for the "everything is a DPS" thing: it would be nice if the Tank and especially Healer roles were more emphasized as well, but I am also after many years of gaming not entirely sure how or even if this is practically feasible.
Healer, in particular, needs to be able to pull off saves, otherwise you're just a maintenance babysitter for predictable routine damage, which actually explains a lot of the discontent among the healer crowd.
Personally, I like WHM for things like it being comfy for some solo tasks, especially Solo Duties which historically were very tense on DPS while healers' self sustain eased the stress a lot, but yeah ... you can't save anyone these days, because everything that's not an instakill comes with a punishment mechanic now, and if it DOESN'T have a punishment mechanic, well ... something happened to player culture in the past 15 years or so and I'm not too thrilled with it. Used to be that standing in the fire was universally condemned - now unless there is some punishment OTHER than straight non-oneshot damage, it's actually expected to the point that you're out of touch if you complain about it. Heck, even Vulns often don't cut it anymore, which is why so many fights have those awful damage downs (or just more straight instakills) ...