I don't think this Lemmy thing is gonna make it tbh. Too many small communities all hoping to be the main hub for types of content, not enough moderation for the amount of fucking around that can happen, not to mention the constant armies of poorly informed morons trying to misinformation the general public.
It's still early days, I don't think we're quite doomed just yet. Right now we're witnessing the Fediverse's initial wild west Cambrian explosion sort of era. I reckon eventually the landscape will settle as people flock to where there are already other people, and tools develop and mature to navigate and manage servers/communities.
Obviously we need human mods to weed out morons and maintain quality, but automoderation and other mod tools for spam/astroturfing/etc. will also make a huge difference. A quick google turned up this Lemmy automod which appears to be in active development, and I'm sure there are plenty of others in the works.