Sounds like you’d have appreciated 90s era irc, which was good for nuanced and sincere discussion, but also did not require talking to people that you already knew.

There’s a sweet spot between open/closed and known/unknown and somewhat focused but not too niche where it kind of works. Theres a certain size that works too, ideally Lots of users and yet occasionally you recognize someone. But I don’t think that’s what people mean at all by group chat today, which regardless of venue tends to be rather more insular and thus echo’y.

In IRC, and as many do here, you used an alias to have the confidence to speak freely. Products like WhatsApp where people reveal their real identities don't lend themselves to that frankness when membership is open.

I very much appreciated 90s era IRC back in the day. I find community comparable to what you described in still-existing phpBB and phpBB-esque hobby-focused forums that I use regularly.