I think lemmy and it's growth is the biggest step forward in the direction of the fediverse becoming "mainstream" alongside twitters implosion As this platform specifically develops more and the front end UI improves in spite of its current flaws, I feel like lemmy and kbin are probably the most likely to be picked up by the general public as it is the easiest to navigate and populate with content. You can federate whole communities in with tons of content, instead of just individual users. There are quirks but I think it has the most potential, it's like the fediverse was made for this kind of platform in mind specifically.

Not everything needs to be mainstream to be great. Sometimes being less known is what makes sites great since you are sure that the user base that is on there are there because of similar reason. Unlike mainstream apps where users trend to be there only because it is hip to be there but don't care for what the sites actually stands for. Hence the proliferation of garbage material in large mainstream sites.