[cocoa19]

It would be nice to take your email address to another provider, the same way it happens for cellphone numbers.

This could be email 2.0... First rule: 1)Do not require host name in the field name. [e-mail] becomes johndoe.

[PureParadigm]

You can buy your own domain. Then when you switch email providers you'd just change your domain's mail records to point to the new provider. You can even transfer your domain between registrars if you decide you don't like your current one.

[me_me_me]

So who owns the username?

Who runs the domain?

The beauty of email as protocol is that its independent. Nothing is stopping you from running you @cocoa19.com (given its non-occupied already).

[cocoa19]

Who owns the telephone number? Same concept.

If I don't want Google to run my email, I just switch providers, let's say protonmail or fastmail, etc. But I don't have to give a new address to all my acquaintances.

[me_me_me]

Government owns the prefix that is rented to businesses who wants to start their phone company (well at least in Europe).

Also the prefix in the phone number is exactly like a domain.

Even if there were no prefixes, one way or another you need a governing body that ensures no clashes occur and has power to decide on disputes. So no two companies try to assign same number to two different customers.