Earlier quoted context omitted.
Better but a the real alternative is what we had before: publicly visible forums, mailing lists with an archive, etc. I'm not going to sign up for your discussion group without being able to get a feel for the community first.
Indeed. There can never be just one platform for project communication, because there are different kinds of communication - mostly sorted between synchronous and asynchronous. So, IRC, Matrix (these can even be interconnected) for synchronous, mailing lists or forums for asynchronous. And of course issue tracker, where some topical communication can happen as well, but that could completely be covered by mailing lis…
Except, that it is easier to set up? What you describe sounds reasonable. But someone needs to set all that up and host it and needs to be trusted etc.
So I guess if many people get involved and do set this up, they would convince the rest of the team to join them. But right now it is just a demand for more work for them.