Classic Final Fantasy UI:
Attack, Defend, Spell (or Skill) and Flee

Ok you need time to choose the Skill or Spell but then you have time to watch awesome movements/animations and sometimes you can influence it with buttonsmashing to gain crit hits.

In most MMOGs you can avoid Attacks by pressing "one" Button - mostly a defence roll or jump... sometimes using a shield or skill to negate/block/counter the attack.

In FFXIV we not only have to move while pressing DPS-Skills, we have to keep one eye on team members for "Markings" and the other eye on Boss-Cast-Bar while we need to avoid different lenghts and most attacks are AoE fields (who had the stupid idea to add unavoidable AoE attacks on top of that?). Thats one reason why players in FFXIV are thinking they need a static group, because as example the cast bar from boss is a tanks job to call out in Teamspeak, or the markings are called out from raidleader or DPS, while the healer keeps track of AoE fields and timing from the group.