Care to elaborate? I'm not trying to provoke you or anything, I haven't played AC but I really enjoyed AA, so I'd like to know what makes it worse.
There are a few things about it that bothered me.
The most obvious is the open world. It's very "samey" in terms of looks and I felt navigating it was more effort than it was worth. The large area in the dead center is also inaccessible at the beginning of the game meaning you have to travel out of your way to go from side to side of the map.
One of the more subtle things was the combat felt like it suffered a major case of feature creep. There are just so many gadgets and specialty moves it gets overwhelming if you are not someone that plays a ton of these character action games. I would be in situations where I knew what I had to do, but all the various button combos had started to run together on me. I really liked the combat in AA as well so I think this was just a case of less is more.
Less is more goes for the collectibles and villains. There are tons of villains and none of them have half the impact even Poison Ivy had in AA. They all feel like cameo appearances. After a while the rogues parade just sort of dulled for me. As for the collectibles there were just so many all over the place it just turned me off from even trying any of it.
Finally, my last complaint is the pacing. AA had tight and deliberate pacing. AC just feels off. Playing hot or cold in a boring open world to find the next objective is not what I wanted from this game.