>>718709997
>merch
Always existed, explosion of merch tied into anime success would be more on Haruhi though.
>otaku culture
Evangelion is a product of that, not a forerunner of it. The first true otaku made TV anime that directly impacted on otaku culture would probably be Urusei Yatsura or SDF Macross. Hell, Otaku no Video predates Evangelion by what, six years?
>"dark" plot with marketable premise
Debatable. One could say Gundam was the one that did that first, even did the sexy flavors of girls (Fraw is the homely girl next door, Sayla is the sexy professional, Mirai is the submissive mothering type, Lalah is delicious chocolate).
>high school tier philosophy
Evangelion did probably do this in the sense that it's one of the earlier works directly focused on concepts familiar to those who would be watching it (namely the hedgehog dilemma).
>doubled down on waifu culture
Sure.