It's true that this is a common theme in Evangelion, but Hideki Anno explicitly rejects this sort of thinking. The whole message of Evangelion is to accept yourself as an individual, with flaws, and to work to change and better yourself with other people, and to form real relationships with them. As is clear from the show, Instrumentality isn't a natural thing. It's not a religious reward. It's fool's gold. Rather than real happiness pursued with other real people, you simply lose all individuality. What's another way of saying you become one with the universe? You die and return to dust. That's all the people who remained in Instrumentality did. To be happy, you must first be, and you qua you cannot be unless you exist as an individual. Otherwise, there's an amorphous blob of happiness, maybe, but it's no better than suicide as you, the self, are gone.