This comment, while oft repeated, is simply not true. There is plenty of symbolism going on in the show. There is a lot of PoMo "mask on top of a mask" stuff going on with the biblical references, but some stuff is more on the nose. There are plenty of articles on this, including this one: https://reelrundown.com/animation/Symbolism-in-Neon-Genesis-...
Eva is a great anime series and a solid 'philosophy exists if you want to check it out' message for 12 year olds that worked for me back in the day, but let's not go overboard with assigning deep interpretations to it.
He's also described Eva as like a puzzle, and not wanting to give answers and instead let people come up with their own interpretations.
I guess what I'm trying to say is I both wouldn't be surprised if he did pull much of the visual symbolism out of a hat, or if he did come across it while exploring western philosophy and decided to incorporate it.
There's some great bits in Extra Curricular Lesson with Hideaki Anno, like him talking about disliking the parts of what he makes he sees himself in or sleeping through a fire in his apartment.
At least the person replying provided some evidence to their counter-claim.
I have no idea who is right, but you're not making anything close to an argument for your point here.