Have you checked the signup page for your Lemmy instance lately? It amounts to "write us a short essay personal statement of what you intend to do here and we'll manually approve your account sometime, hopefully soon." I know this is somewhat standardized among instances, and it's there for a noble reason, but it's without a doubt friction for everybody who goes to sign up, and a barrier to entry for a good chunk of people, who might not yet even fully know why they'd want to join aside from "my friend says this is cool."