I know this is a minor gripe, but I really dislike the Aquatic Ruins Fractal. Specifically the boss fight. I know that you're supposed to lure the boss into the electrified cages, but this mechanic just doesn't work. It takes too long to pull the boss to any of the cages to make this strategy worthwhile, and usually by the time the boss gets there, the cage is no longer electrified and another is on the other side of the arena. So every group that does this fractal just uses DPS on the boss and ignores the electrified cage mechanic entirely.
Two minor changes could easily fix this. First of all, don't cycle the cage until the boss has hit one. Just keep the same cage electrified, and only after luring the boss into it, should a different cage activate. Secondly, make the boss chase a player more actively, and put an aggro marker on the player so we know who it is chasing. This would also make the boss a little more of a challenge. Right now it just spins a lot in place, not doing much of anything.
Optionally, the boss could even have a new phase where luring it into the electrified cages, is required to make it vulnerable. But this is provided that the cage mechanics overall are improved first.