I occasionally go back to reddit for niche communities and for looking up some user generated information/answers. I think the niche community might not easily be solved until more people move to lemmy, but as for the information lookup, if we can port the more useful stuff from reddit I don't think I'd have much of a reason to go back to reddit (seriously, so much of the newer info in some subs are factually wrong but no one seems to care and it just seems to get worse the longer time progresses). The main issue is how to figure out what is the useful stuff. Idk about Twitter, haven't used them in years.