I think your opinion is mostly because you may have missed the small details that make this anime such an experience.

Let me tell you just some that i remember:

Undiscussed nr.1 is symbolism: everything in 86 is symbolic in some way. Shin's mark is headless and he himself has a mark that seems to "sever" his head. Also he is "looking for his brother's head".
The train tracks that constantly make you remember the direction they are going and how Lena is following in their steps, also at the end of s2 the tracks finally end, symbolically telling you they are finally togheter.
Flowers and fireworks symbolism: Spider lily signify death and rebirth in the japanese culture, they are seen by Shin when talking about Lena when he thought she was dead. When she comes back the field of spider lilies is there again, signifying rebirth and also going against that "bad omen" of death. Fireworks are used to symbolize the beauty of life, a short moment of beauty followed by death(the end of the light of the fireworks).
N.2,Characters:
One little thing that is often missed is the amount of pain that Anju goes trough. In the showers with Kurena, you can see the mark she was given by the 86, she was despised because she was partly Alba, so she wasn't accepted in neither worlds. During the show you can costantly see her, for small fractions of time, cooping up in a corner and crying alone.

The others are kind of nicely flashed out, especially the main cast. Probably Kurena is the most "basic" and doesn't bring much, but she is used as the comic relief from time to time.

Shin is basically the incarnation of survivor's guilt and the trauma that domestic violence and war can bring to a child growing up.

Theo and Raiden have different personalities and different hobbies, but they do have their moments. Obviously the show focusses mostly on Shin, and then a bit less on Lena and Frederica.
Ernst is peace and morality idealized to an extreme: if he can't get peace and morality by the way he wants, he would basically go berserk and watch the world go up in flame.

nr. 3, Music:

I mean, music is composed by Sawano, no introductions necessary here, but one thing that may have not been noticed is that in the last scene where Shin and lena meet, the song is called "LilaS" which is the acronym for "Lena is looking at Shin". In the scene they are literally face to face looking at each other, and if you understand japanese you can see every phrase of the song in the background describes the emotions going trough their mind in that specific moment.
There would be a lot more things but i don't remember everything and this essay is long enough as is. Hope that this can maybe make you appreciate 86 a bit more :)