Its ffxiv combat really so slow and boring?

[Yzuna]

So, aesthetic > gameplay
...
to be honest, aesthetic questions are always the last thing i am asking myself to consider a game... Far after things like gameplay or leveldesign

Well, same for me. But feel that your skill have impact is part of the gameplay for me.
Skills/spells with longer Cd and/or build-up but with more impact on the fight could actually be interesting. More so if you had to time those skills right (waiting for significant buffs, synergy with other PT member, timing for boss weakness etc.
Right now, you are using almost everything on CD, without really thinking about it.
They tried this, like with Ninja weakeness debuff, but all in all, it doesn't really change much, and you almost never should delay a skills to wait for debuff/buff.