Users can sign up using nothing other than a connection with a previous app/wallet (i.e. Twitter or Metamask) and start using LeoFinance/Hive without even downloading their keys and learning about how all of that stuff works.
I think, most new users will want this only - However, why can't we use the phone as a second factor auth even though you store everything ? Most sites now a days leverage on OTP for sign up. That's the most convenient option of authentication with less chance of compromise.