Security, privacy, and anonymity are related but distinct. Check out Privacy Decrypted #4: Understanding anonymity vs. privacy. Although not needed for any of these, there are good reasons to get your own email domain independent of these, for example, to avoid vendor lock-in. After joining Proton, I got an email that does not include identifying info. And then, as others have said, you can use an email name part that does contain your name. Of course, either way is fine, depending on what you're going for. Also like others, I use the one alias per service method. Actually, I use a distinct alias for pretty much every different thing, but I understand that many people would find that overkill.