And the grandparent's comment about there being boards for other topics is why the radicalization is such a problem (the same thing applies to Reddit and Youtube's recommended video algorithm). The normal content is what attracts people to the site, but once there, they see the radicalized content mixed in with it. This ends up normalizing the radicalized content making it easier to recruit new members. Very few people will go out of their way to go to the Daily Stormer or some other site dedicated specifically to hate. But it is easier to be lured in when that content is just a part of the site.

Isn't banning/silencing communities like these the real radicalization?

Has it occurred to you that radicalization actually happens offline, perhaps even in childhood, due to some kind of real life events, and nothing to do with internet at all?

All of this rooted in meatspace. The so called "social defeat".

How often do you see successful people that have a fullfilling life go on rampages?