I don’t know that Mastadon needs to be bigger, but lemmy really needs to grow to compare with reddit. I mean there barely is a photography sub for instance. No travel one I could find, or anything like bifl… And then getting the niche community together. I guess there may still be web forums out there. Personally I liked those, but they are actually more isolated because they don’t federate at all. So lemmy is potentially a feature improvement over phpbbs etc. But you still have to build the communities and get people who are into X but aren’t tech people to those communities.