While WoW may have much fewer buttons, the gameplay is deep (at least on my Ret Paladin, I know I know). I have a lot of optimizations to make:
1) Don't cap Holy Power
2) Spend procs so you don't waste them being overwritten by new procs
3) Have to spend Holy Power ever 4s to maintain 15% damage buff
4) Don't let CS sit on 2 charges
5) Use abilities in an appropriate priority so you don't get stuck with nothing to do/deal less damage (not sure how many classes have this issue, but it's a Ret one since it's a priority based cooldown class with no filler attack)
6) Priority changes during DPS cooldown with addition of an extra attack
That's just the baseline stuff. This changes depending on which talents you select, which azerite traits, trinkets, and Necklace powers you use. For instance, due to my traits, during my DPS cooldown, I have to prioritize spending Holy Power over a more fluid rotation because I have an extra generator and button forcing more clashes. Not only that, but the increased crit chance I get from it, props up my other azerite trait that deals DoT on a specific ability crit, but that ability can proc back to back, but I have to delay it so if it crits it doesn't overwrite my Dot (all while trying to not overcap resources/let abilities sit idle).
Each of these elements on their own are pretty shallow. Don't cap resources, spend procs, don't let abilities sit idle, etc. That's FF14 gameplay in a nutshell too.
But where it does shine is how they overlap and layer over each other. Each decision points interacts with the others, whereas in FF14 they do not. They're consistently binary (some exclusions, like BRD/BLM come to mind, and an example of why I always say that I feel FF14 does casters MUCH better than WoW does). You will NEVER hit Fast Blade after Riot Blade. You will never hit True Thrust after Disembowl. That's not a choice, that's forced gameplay.