They should have separated identification and content.
Make a unified id system and then let people host their own communities on the federated level.
This would have been expecially important as you can't really move your account among instances, and would have make the registration process also much easier for normal users who just want to use the platform
The only protocols I've seen which do this require users to use PGP/GPG keys. Its very definitively not user friendly. I'd rather the Lemmy and KBin devs emphasize their focus on other improvements rather than reinvent how the fediverse, including mastodon, does authentication
see I always expected it to be like a "well, first you gotta have a MariaDB or Postgress" then "you'll need to configure nginx" followed by security gobblygook , and if you want a UI you'll have to figure that out on your own
Or join a specialized instance and create a username that the people in that instance will understand but not the normies. (For the record, yes, this is my lemmy.world account, but my username on startrek.website is much more obscure than this one)