Government-backed email would also help solve the “is this a bot” problem by limiting the number of email addresses that can be used, though naturally you’d also lose anonymity using that email.

There’s also the issue that if the emails are predictable, spam and phishing become much easier.

I’m mixed on this one. If we could choose the username and there’s no API for anything other than “is this a person” and your classic IMAP/SMTP stuff, then I’d be a lot more on board I think.