Every game needs a Baseline of skill and what OP suggest is just 1 Button Win and thats no longer participating in the game its more like getting entertained without input and thats just a MOVIE. And like other already said the difficulty is good and based on average and even a little below that.
Sorry but for somebody with average skill no normal difficulty fight will impose any challenge in FF14 for that reason we have Extrems and after that Savage and further down the line Ultimate's.
What is expected from the player is: Read the Tooltips of your Job, watch the boss and watch the arena, avoid Orange.
Is this too much for somebody Lvl 90 ?
You want no difficulty but FF ? Watch a movie - i know thats blunt but this game is not hard on normal and all suggestion i read so far would make all trials or 8 man stuff to a movie and remove the input from the player almost completly.
Thats not "nerfing" thats killing difficulty with a nuke.