So… everyone instead just went to Bluesky and Threads where sign-up links were provided rather than directory links and manifestos.
Wild! This was my exact thought as I was signing up for Mastadon. I spent like 15 minutes figuring out what Mastadon is, what server to join, what each server means. Then I did the thing like I did with Lemmy and created half a dozen accounts waiting to see which server gave me my “Account Created” email first.