I despise the direction Attack on Titan went in the later seasons.
I was really into AOT when it first came out, both visual and novel form but really hated the direction it went. I stopped watching halfway through season 3. No particular reason. I of course at the time of the rest of series being released heard about what was going on and it really didn't compel me back to the series.
I hate how the series pivoted to complex geopolitical conflicts with Marley, Eren's whole ouroboros about trying to fight change, etc.
What drove me to love this series initially was the whole post-apocalyptic mystery of the world. Humanity fighting for its survival against monsters. And as the series goes on and slowly points the monsters to being man-made that made it even cooler. The possible authoritarian society established to subjugate the majority of Eldian's through fear, oppression and isolation. Suggesting that this was a sort of ploy from the rich and powerful of Eldian to stay powerful. Perhaps even a punishment from years ago for a potential civil war they created. Or that the corps even have this tier system where the scouts are used as pawns to die while the other corps closer to the inner walls don't come close to the scouts.
It just felt like a whole different series when they involved the Marlians. I'm not even fully against the premise of some sort of war, etc. If it stayed within the themes of what the series was originally.