The late game is not fun. I stopped playing in Act III. Trying to figure out why.
I don't like that I've been level 12 for a long, long time. The game hands out way too much XP. Max level means you have nothing to look forward to anymore.
I don't like the way anyone looks. The best armors are all completely overdesigned. The party looks like old money and posh, instead of a real fighting crew. All weapons, and Wizard staffs look weird and over-decorated.
Items are completely out of whack.
The Helm of Balduran is ridiculous. No matter how much Hellfire Raphael throws at me, my Tav just keeps going. I'm winning only because of one OP item that makes me unstoppable. Winning that fight was not satisfying. It was anti-climactic.
Karlach is dealing outrageous amounts of damage with Balduran's Giantslayer. Nothing else even comes close. The weapon overshadows all character abilities.
Armor of Agility is so OP it just breaks the AC system entirely. As is Helldusk armor, a full plate +3 that ignores proficiency requirements.
I don't like how the "best items" break the rules and are so far and beyond above everything else.
Spells don't feel powerful at all anymore, just when 6th level spells should be amazing. The best way to beat everything is to deal stupid amounts of weapon damage, with stupid amount of haste / bonus attacks. Chain Lightning means nothing.
Enemies start having powerful lore-detached abilities like Unstoppable that belong in an arcade game, not D&D.
The camp is ridiculous and has been for some time.
How many nightsongs, mizoras and withers can you have following you around? Don't these powerful plot NPC's really have anything better to do than hang out at your camp? Mizora summons more devils to camp and Nightsong has nothing to say about that. Too much special in the camp breaks immersion.
