As somebody who is guilty of this, my rationale is this: I went to slack/discord/IRC channels, asked for help and... almost no answer. Ask the same question in a comment of a popular issue or a new issue, and you get your answer (with some delay). The thing is that GH issues have replaces mailing lists/usenet for this kind of questions since the friction is way lower, it's async and the question goes to the right people.
There's a discussion feature on beta (see https://github.com/BurntSushi/ripgrep/discussions for example)
I'd definitely like this to become public soon