A major cause of email overload is that senders don't respect the "you can read it on yours" part of that statement. Instead, they send emails requesting info that they need to act on within a specific window of time (usually hours or days). This implicitly assigns recipients a time limit, because responding too late would be considered rude. If you're receiving 500+ emails a day that expect a prompt response, you don't stand a chance.

Communication works both ways. If you can't be bothered to take my schedule into account, then don't contact me. Complaining about this is akin to complaining about someone having a secretary.