I agree partially but I think a lot of people - myself included - don’t necessarily check back to their own comments. And there’s no notification- which I’m sure is a feature more than a bug.
I guess your texts being public is a matter that affects the nature of conversation. But I'm sure we could hack this together with a "post your phone numbers" post
Honestly I wouldn't mind a good ol' fashioned global group chat. I know there are moderation issues there, but I miss IRC and want more of that feeling elsewhere.
There is a #hackernews on Libera.chat, and I believe I've seen a #ycombinator (or something similar) somewhere. No idea how official they are. But every HN-based community I've seen was a ghost town outside HN itself.