I bought a domain and started using it for all my email last year. It’s the best and I suggest it to everyone.
The combination of your own domain, Fastmail, and Bitwarden is powerful.
You can move email services by changing a few DNS records and Fastmail has an API that Bitwarden hits to create new masked email addresses using your domain so every site gets a different email address. Start getting spam? You know exactly who leaked/sold your info and you can now send that address right to the trash.