Yes, this. I've had my own domain for about 20 years. I've used that domain at gmail, a brief attempt at self-hosting, and at fastmail for most of those years.

Yes, this. I've had my own domain for about 20 years. I've used that domain at gmail, a brief attempt at self-hosting, and at fastmail for most of those years. I've considered proton, but I'm happy with fastmail. Moving my email hosting while keeping my "identity" is one of my primary motivations. That said, you don't "own" a domain, you only rent registrar services. If you miss a payment (mine is automatic) or become notorious, you could lose your domain. Still, it's the most practical foothold for most of us.