TBF, with the exception of 4chan, these are all microblgging platforms occupying the same problem space. Lemmy is more like Reddit (unmentioned), which is not only more long-form, but has a different mechanism of organization: people self-organize by topic, not by following personalities. Lemmy & Reddit replaced Usenet. Twitter et al were a new, different paradigm.

4chan is in there to be funny, but shares more with Lemmy and Reddit than micro-blogging sites.