@paulox @matrix great topic! btw https://gitter.im/ is run by Matrix. So I think a lot of people are already using Matrix without fully realizing it.
For me, the answer is "gradually" and I agree that other platforms like Zulip and Discourse are necessary to take into the picture.
Regardless, the community risks more fragmentation. But I don't think that just jumping into it and starting a Matrix server is the answer, it requires some support, facilitation and planning.