Earlier quoted context omitted.
We did, it's called non-disposable email. A non-unique pseudoanonymous identity that's somewhat difficult to mint in bulk. If you don't like "accounts of well-known service providers" -- email or login-with-whoever then sources of identity that "everyone" has that are hard to get many of are government ids, phone numbers and credit cards. Like what else is there? For super technical people we could do something like…
I don't really get this. Where do you draw the line between disposable and non-disposable email? What prevents anyone from creating @gmail.com addresses?
As of gmail -- one of the guidelines for the list addition is whether you need to go through some sort of a registration. If you do then it is usually not treated as disposable by us.