Earlier quoted context omitted.
FWIW, the book The Identity Trap by Yasha Mounk attributes the popularisation of what it calls the Identity Synthesis to social media such as Tumblr, then later Reddit, Twitter, Instagram; and web sites such as Thought Catalog, later Jezebel, xoJane, Rookie Mag, and the Daily Dot, then everydayfeminism.com, Salon, Vox. I think it's conceivable that, while these ideas on the left and right later entered all social med…
I would posit that the proportion of "originated from 4chan" notes on knowyourmeme.com are an indicator of its outsized influence.
You can find discrediting examples in the mid-2000s thread collection the internet archive recently released ("archive ten billion"): memes appear in the chanological record years before they anywhere Google knows of. But how can you know that's the real origin? Even "Know your memes" first appears in there as a /b/ catchphrase in April 2006, but you must notice that's also when the /b/ posts in the collection begin.
Edit, another example:
4chan is also known as a Mongolian basket-weaving forum, among other things: corruptions descended from the meme of referring to anime as "Chinese cartoons". An old 4chan saying, as KYM finds? No, it came from that Russian anime newsgroup, ru.anime.chainik, after its parody FAQ from 2002 was translated by users of an associated LiveJournal group and added to a since-deleted Uncyclopedia article.
Q: Что такое аниме?
A: Китайские порнографические мультфильмы.
The full FAQ is on the author's website, which is still online, shounen.ru/anime/tech/afaq.shtml But is it entirely original to that newsgroup? Some of those terms seem to have come from FIDO...