I think what would end up making this a viable platform for the average person is an elegant app (Think Apollo) that initially obfuscates the whole concept of federated servers. One where you create from within it a “Lemmy” account/address and pick what domain you want. Defaulting to lemmy.ml perhaps? Or suggesting a server based on a short questionnaire, like what Twitter does to recommend accounts to follow. Being able to use that same account on various federated platforms would also be pretty cool. Most people will need to have their hand held or they’ll never leave behind what they are accustomed to.