NIP-01 defines “name”, it would be nice if all clients just used that and nothing more. I think the confusion and all other fields comes from it describing to put a username in that field, instead of just name so people invented other fields to put names.
There are way too many name fields, agreed. I would be happy just seeing “name” and then let NIP-05s be an additional way to reference a user. We already have npub, it’s too complicated to add more than that. Who goes first to start removing some of them?