Here we go again but I guess i'll bite:

1) What threshold would constitute challenging enough for you at endgame? NM raid level? Occult Crescent CEs? Extreme trials? Where do you set the bar?

2) What about players that get left behind because they cannot follow yet play for the story? Do they drop out of the game when they reach a wall?

3) Maybe not everybody is playing the game with the same goals than you, maybe some aren't playing the game to turn it into a homework or want to study the blade and improve until they beat something they can't? What makes it rewarding for you may not feel rewarding for others? For example for me, it's not beating challenging content that I feel rewarding, in fact even when I beat my first extreme fights or savage fights long ago I didn't feel especially anything about it. But on the other hand making the proper choices within a battle system that I liked, playing my job well (well, when jobs used to be engaging that is), that was was made me pumped. And ironically this happened a lot more in casual content that has always been less scripted than harder duties.

4) I think you're gravely mistaken if you think that accessibility has nothing to do with usability, personal abilities and ergonomics as well.