Attack on Titan's final episode of its final chapter in the final season has finally arrived, and it's even more complicated than its release schedule. As the series' finale came to a close, all the complex interwoven threads of Eldian, Marleyan, and Titan history collided, and it all led to an exciting – if at times confusing – ending. As far as the manga is concerned, the series' ending is widely considered controversial. However, the anime adds to and changes aspects of it that don't take away from its message, but instead were "pretty much there from the beginning" according to AOT’s creator Hajime Isayama.
Source：https://www.cbr.com/aot-anime-ending-explained/
