https://aeon.co/ideas/what-did-hannah-arendt-really-mean-by-the-banality-of-evil
Reading this article it seems that in recent decades more and more dissenting voices of her view have come forward and that her initial analysis was flawed.
It also strikes me as peculiar how she mentions that Eichmann did not think of his actions as evil, as he could not view his actions from the viewpoint of his victims, and that this is proof that he was "normal". However, doesn't this lack of being able to emphasize with others show that he was a Sociopath, so very much not normal?
This answer by u/commiespaceinvader has long been a favorite of mine, and it should help answer your question too, as it focuses on how Arendt came to her thesis and what some shortcomings of her analysis were. I would love to see answers from others regarding even more recent developments and/or the character of Nazi bureaucracy as a whole, though.