We’re talking about discord and why people use that and not other technology. 99% of the people on discord are not involved with FOSS, but they are what make the platform attractive.

programming.dev is useless and serves no purpose?

No, this instance is federated and not a traditional forum.

A budding community must be online 24/7 to provide support

No, it’s fine if that support is given via the git platform, and it’s also fine if it takes a while. And it’s also fine if the question goes unanswered.

imagine a community with many people and the chat moving forward quickly enough for your question to be out of scrolling view within minutes due to other discussions going on. Even in that scenario there is “no purpose” for a forum?

Yes. Because it is functionally no different than a forum main page where so many new topics get created that questions people don’t get to get buried. And also, I’ve never seen that happen. What I have seen is that people didn’t have time or interest to answer my question. Which is fine because they owe me nothing. But a forum would not have “solved” that.