I only pointed it out because it's not a great blanket statement because it gives the impression that there is something inherent about email that means it is stored as plaintext. I fully agree that security is hard, and securing against a government while operating within their jurisdiction is just about impossible, but your email may not be stored in plain text.

Just as an example, ProtonMail offers encrypted email with protection that is good enough right up to the point that a major nation-state takes a very strong interest in you. They're based in Switzerland as a means to make it more difficult to compel access to user data. Nothing is impossible, of course.