Since a recurring subtopic is button presses, let's look into it a little more. I decided to match the Shadow Priest casts with one of the top DPS for E2S. They're a Bard, so it's range and range. To prevent naming and shaming I will not quote the player's name but you can verify yourselves by looking through FFlogs.
This image here shows the Shadow Priest from the first boss in Mythic The Eternal Palace
This image below shows one of the bard I'm using as an example from E2S.
Both of those are range classes and not really a unique rotation to say. Not a vast difference until we look at time. In the Priest's log, they used 263 actions in 3 minutes vs. the bard using 396 in 9 minutes on E2S. If we took the same pacing of 263 buttons every 3 minutes while tripling the same boss's HP, the Priest would've done 789 buttons in 9 minutes. Which would match the Bard's kill time on E2S.
Both fights relatively don't have players moving very much besides a mechanic here and there requiring you to stack on someone moving the AoE out or standing on your soak marker in E2S and dodging the combo in the last phase.
If we look at this, the Priest was doing 90.5 CPM and the Bard is doing 46.6. We could go into the nitty gritty of which classes are spam classes but I believe that is a different category of issues, balance and game design over time. Neither side are wrong to play, which we all can agree on; however, for the above average player, WoW is considerably faster in CPM to FF14's CPM, even if it's 2 extra buttons. Which, CPM aside and only looking at rotations, is a personal flavor difference for each player themselves.