In our classic internet you have a domain name which is totally centralized. Using email is a decentralized solution. You can create and change your email address million times with no cost.
No, using emails is not decentralized solution all data is stored on one centralized server, and I can also create million of domains if I want including some free domains.
Even worse than using emails would be usage of mobile phones as some kind of ''nodes'' and you didn't explain how thot would work but it all reminds on that junk Pi network.