It absolutely existed 20 years ago, and not much about it has actually changed since then ideologically or even stylistically, but it was mainly confined to UseNet, which the vast majority of internet users could safely ignore (or could not figure out how to access) and which mainstream media almost never covered.

It has been built piece by piece by successive generations of increasingly unhinged alienated weirdos.

Well yeah. Because they had way too much time on their hands. They wouldn’t have in the past, even if the internet had existed.