From a personal perspective, I absolutely agree - I only check my email when I'm specifically expecting something, which is rarely. But at work emails are still incredibly important.

Are there any protocols/services designed specifically for one time codes? Receipts? I think something that's dedicated to those kinds of tasks would be great from an ease-of-use perspective - no more messing about waiting for delivery, searching through hordes of emails, checking spam folder, etc.

Another problem we have is the rise of oauth - the core idea is great, but the reality is that it ties a lot of people to these Big Tech services.