I guess the thing that really changed is our tolerance for bad actors. As far as I'm concerned even a 99% signal-to-noise ratio is unacceptable if the 1% represents a contingent of determinedly obnoxious and hateful people, and 4chan was never anywhere close to 99% signal.
Nah, the board culture really did change in the last 7 years. In a past that's not too distant nobody was obsessed with trans folk. That's not to say there weren't vulgarities and unpleasantries, but there was definitely a substantial IQ drop somewhere around 2018 and 2019. I haven't seen the "Install Gentoo" meme in a while, the old board culture was basically replaced with cringe fringe zoomerisms.