My email address is not just for email. It's so firmly embedded in my digital life, it's hard to think how to remove it. It's my identity. I use "login with Google" in most places where it's available. It's my backup recovery for my MFA authenticator. It's my github alias.
So what is the strategy everyone follows to start with a custom domain? Do people use redirection? Is that effective? What happens when an email is redirected from Gmail to my new host, and I want to keep replying without the recipients thinking I've changed email? If you do that, is it even worth switching, given you have to keep your Gmail account?
That is the more interesting part of these stories to me than which host people move to.