I've got no friends to play with and I'm not great with micromanaging cooldowns on 30 spells.
This is why I also prefer action MMOs instead of the play the piano clicky mmos.
I've played Vindictus for ~7+ years and that combat system is still my fav till this day, most of your combos are based on mix of left and right click of the mouse and just a few skills on the skills bar.
Whatever else left is keyboard based, combat is more focused on timings like knowing your dodge's invincibility frames to avoid attacks and such but its just fast paced in general so it keeps you engaged in the fights.
'also pressing buttons in the right order/timing to pull off special stronger attacks of specific skills/combos'
Too bad they ruined the game in general but that combat system is still what I'm looking for in MMOs but eh most of them are either too piano/boring style or way over done/complicated for my taste.
Blade&Soul was my second best I guess, it had a hybrid system that was both skill bar and combo based but not overly done imo.
I'm gonna play Lost Ark when its relased but thats more of a ARPG style of control so thats fine with me since I grew up playing that genre.
'not too many skills to manage either'