Most online accounts identify users using email/phone & password; but since most all email/phone is handled by another service (e.g. Gmail), one's online identity only exists so long as these services permit it; in a sense, the service owns the identity, and the user is just 'borrowing it'; or at least that's how I see this.
So if a person loses access to email/phone account and the services refuse to help recover it (be it for valid/invalid reasons), there's little one can do. Now, there are many factors to protect against the loss of the account (e.g. strong passwords, 2FA, reliable company, etc.) but managing risk is more than just prevention; there is also recovery.
The only close-to-guaranteed way I can see to recover an email, is to self-host it; even if the email server gets compromised, it can be rebuilt fresh/securely and life can go on. (For this question, not treating compromised emails as a major threat - the main focus is on the actual email account; not to invalidate that concern as it would be a big deal for say an online crypto wallet, but just not in scope of the question)
Now it's not perfect (dependent on the domain, ISP, etc.) but it cuts out a major middleman. Of course, self-hosting an email server is easier said than done; managing it and keeping it secure is not trivial.
Which brings us back to the question: if my statements and conclusions above are reasonably accurate, then is self-hosted email the closest one can get to owning one's online identity? I'm aware of a few concepts (see prior art) but unless you live in the right country or in the future, it seems today this is the most (if not very) practical option.
Am I thinking about this right, or are there more resilient alternatives (e.g. cut out more dependencies)? Or maybe comparable but easier alternatives?
With government support, could do a legally backed identity like Estonia: https://en.wikipedia.org/wiki/Estonian_identity_card
Conceptually, I think what I'm asking for is self-sovereign identity; which apparently blockchain could be used? But not aware of any practical examples yet: https://en.wikipedia.org/wiki/Self-sovereign_identity
Focused on implementation, but not asking if there are alternative approaches: Dedicated domain for email registration