Before self-hosting your own, first get a domain and just point it at a mail provider that allows custom domains. It will cost, but so will a VPS. I suspect a lot of DIY homelab types would have most of their needs met with just that setup:

- you get the vanity email address

- you can switch email providers (including self-hosting later on)

- you can have ~unlimited aliases (depends on the provider)

Most of the setup consists of steps you will have to take anyway when self-hosting (getting a domain, changing DNS records), except for a major amount of headaches that will be taken care of for you.

Agreed. Also being able to use as many aliases as you like (or a catch-all) is very nice.

Agreed. Never use a provider-specific email domain, when for a tiny amount per year you can have an email at your own domain that stays the same no matter who your email provider is.