Just throwing my 2c in. This sounds cool in theory, but after a couple years of doing the same thing, I've identified exactly one case of an org giving my email

Just throwing my 2c in. This sounds cool in theory, but after a couple years of doing the same thing, I've identified exactly one case of an org giving my email address to a third party, and it was a local car dealership giving it to siriusXM because a car I bought had hardware for the service. That said, I absolutely love Fastmail and having my own domain for emails.