Should we push for an email portability and a framework of regulations to support like, like telephone number portability?
There are obviously some interesting technical problems to be solved, but it would be great if I can switch providers without having to update my email address everywhere.
The technical solution already exists. Get your own domains, point them to a provider of your choice, set up forwarding on google/yahoo to your new domains. Go through all your services and change your email to use the domains you control. If the provider becomes compromised, toxic, etc... you can change DNS to a new provider. Use imap-s to back up your folders so that the email provider can't leak your data.
I believe that assumption is a misapplication of email. Universal identity is a complex issue, and is not addressed well by email addresses. Portability is one example.
Also the cybercrime crisis, which is substantially enabled by email phishing, may well drive email off the public Internet. We no longer need an Internet messaging system which makes you accessible to everyone else on the net, without consent or limits.
For a next-gen take on Internet messaging, see the mnm project, which proposes and implements TMTP. That system supports separate site-specific identities for every user (and multiple aliases per identity), which is a better match to the real world.
When google shuts down access to an email box, If it continues to 200 OK accept SMTP, its potentially accepting contracts, warrants, government communications...
Most providers offer email export and import. So you can also move emails between providers.