When you continue reading beyond this presupposition, the author does not conclude we need better or more accurate censorship. Instead his point is that we need

When you continue reading beyond this presupposition, the author does not conclude we need better or more accurate censorship. Instead his point is that we need new ways for building consensus that crosses partisan lines. Then he hypothesizes mechanisms for building this consensus without needing censorship. His point regarding free speech is that, in the current world, bad faith speech, self-serving speech and the suspicion that speech could be bad-faith or self-serving, are breaking our ability to reach consensus. This is bad because it immobilizes politics unless someone 'wins' which only serves to mobilize the faction who 'lost'.