Re: "death of email" ? not until chat gets federation!
Exactly what they do.
I had a catchall on one of my old email accounts (anything that was not sent to a specific list of email addresses got sent to a "sink" account). Sometimes mails in there would be typos of a "proper" address of mine, but mainly they were random - sometimes peoples names other times just word(s) from dictionary - few obvious ones e.g. sales, support, marketing, admin, HR etc