Intellectually, I think lemmy already has a good grasp on topics...but I do miss the daily video content of r/crazyfuckingvideos, r/publicfreakout, and r/idiotsincars.
Something I think is genuinely useful about Reddit that I don't know if Lemmy has replicated yet is the whole genre of "The entire world is here, someone will recognize what you're talking about" subs. What is this thing, what is this bug, tip of my tongue, tip of my joystick, ask historians, ask mechanics...I'm not sure we've established that brain trust here.
OP, please don't go making empty ghost communities based on the feedback here. That would be worse than no community at all. Communities should be created by topic enthusiasts.
personally i'm missing all the horror content. there's a nosleep replacement here that's gaining traction but stuff like /r/wtf, /r/oddlyterrifying, /r/creepywikipedia etc are sorely missed right now
pretty much exactly what it sounds like. people would browse wikipedia and post the creepiest pages they found. like, for example, the aztec death whistle.