If you own a site that has systemic issues with child pornography sharing and other illegal material, you probably deserve it.
Yes, there are points in time when posters have attempted to post child pornography there, but it gets taken down swiftly and gets reported to moderators as swiftly as its posted.
Your "epicentre" of child pornography on the Internet is Facebook, not 4chan.[1]
[1]: https://samharris.org/subscriber-extras/213-worst-epidemic/
8chan being dropped showed well how cancel culture works, and how in the court of public opinion one is found guilty not on evidence, but on sensationalist news articles that outright lie, sitting free from the pains of perjury and cross-examination.
I have not once in my life seen this child pornography or far-right content on 8chan that these news articles claimed infested it; one would have to be very lucky for the former to see it before a moderator removed it, and for the latter one would have to specifically browse niche boards that have very little activity compared to the big boards, which are simply about video games, lolcat image macros, and dating advice.
Have you ever seen child pornography on 8chan or 4chan? have you ever browsed them?
By your definition of child pornography, i.r.c., and Mangadex also feature child pornography, as well as Google search results and most mainstream pornography websites.