Evangelion is not overrated. It deserves its spot by what it did with the series with the original ending.
All the characters in the series aren't characters, they're emotions. The entire show was the artist communicating directly with you on how he views himself, the world, and society ; and the question about what is the meaning of life and why?
That ending has a profound impact on millions of peoples lives, and we're talking about repressed Japanese people who are not allowed to express these types of thoughts and feelings publicly.
For the time this series came out, it was groundbreaking, and there aren't many series who tackle these hard topics, especially not as a giant twist in the last few episodes. The show is really not for kids, it's for adults, the themes will fly over heads unless you're mature and probably depressed looking for answers to questions you're not even aware you're seeking.
Evengelion is a refined series that'll stay relevant for decades to come, and the intro song is a banger.
If you watch it any other way, it's a subpar anime. But if you watch it with the intended ending and purpose, it's amazing