Something happened in the post-2010 times along with the Tea Party, and offensive humor - especially overt racism - became a mainstream part of conservativism, all the way to the White House.
> "jokes" where the punchline is "I hate my political enemies"
Hence the laughter in the White House at refusing to follow the court order to return their political enemies from the overseas prison.
4chan may have died, but Trump is more the first 4chan President than Howard Dean was the first "internet candidate", and especially Musk the Twitter Presidential Vizir is the heir to this culture.
Of course, in a post-Bioshock Infinite world, there's really no excuse for not grokking how time and distance from the origins of a cultural behavior pattern can warp even well-meaning notions that aren't regularly re-examined and tuned to align the intention with the zeitgeist. If the Sarah Silverman-esque posters ever looked up and realized, "Oh, they don't know it's a joke, they're ACTUALLY Nazis," it was too late to shift things back. (Unless you were in a Boondocks thread on /co/, in which case correction was freely forthcoming.)
Probably didn't help that at least one mod wanted 4chan to become more racist, on purpose.
I’d suggest taking off those glasses as they are a bit too rose-tinted. I was there, just like you, and the humor was way more “childishness” than “creative irreverence” well before 2010.
Mostly because, as more people came online, they mistook offensive humor for conservatism; and thought "counter-culture" meant "being opposed to the political party currently in power", rather than "being opposed to political parties".