I used federated services like Mastadon before its own "Eternal September" and it feels to me, subjectively obviously, as someone who was on the Internet when Gopher, Telnet, MUDs, and USENET were basically it (except email) that there's this new obsession with moderation and walling off networks. Whatever happened to self-moderating? I have higher standards for my speech and on-line conduct than any TOS. Many others…
You see a similar effect in spam. It would be a vast waste of your time to roll your own spam engine. Killfiles aren't sufficient; they spawn new accounts instantly. Spam used to dominate email, until big email hosts developed ways to shunt it off. And that requires constant management as the spammers find ways around those filters.
I'm glad for dang's moderation here on HN. I wouldn't come here if I had to roll my own killfile. It doesn't just keep the worst offenders away. It also keeps the conversations on topic, rather than degenerating into flame wars.
Moderation is of course imperfect, just as spam filters are. But without it, I find any open communications medium unusable. The loudest and most obnoxious voices dominate, effectively creating a different kind of censorship that keeps out the things I actually want.