Hacker News Reader

This is the shit company that bought vBulletin and ran it into the ground.

And many big forums (and immediately stuffed them full of keyword advertising)

Is there a good FOSS alternative?

phpBB is a long standing project similar to VB. One could also use something like Lemmy or Kbin, though they have a different style and focus.

vB itself isn't FOSS. XenForo is the best alternative by a fair margin, but for FOSS there's good old PHPBB.