I would not say the game needs a challenge. The game has hard content already, much more then XI if you do not count AV.

What it needs is depth in its systems, long term goals, and content that last longer then 1-2 months.

The blm pic someone posted says it all. This game is just ultra shallow and it is not just the battle system it is every system we have. Complexity for the sake of complexity is bad, but no complexity is just as bad.