As discussed in a recent comment I made [0], I think the problem is that a good modern forum software simply does not exist yet. imo discourse doesn't cut it, feels almost as ephemeral as in slack/discord.
Zulip [1] is open source and (IMO) fantastic.
Correct me if I'm wrong, but I think they're working on creating public chats, readable without logging in, from the browser?
Yes, the web-public view is being actively worked on: https://github.com/zulip/zulip/issues?q=label%3A%22area%3A+w...
There’s also a separate zulip-archive project that exports Zulip streams to static HTML: https://github.com/zulip/zulip-archive