Good point, if you aren’t using the radio, why not just use your regular email client? There are a couple of reasons for doing it this way.
The Winlink organization also maintains a complete global infrastructure for processing these emails over the internet, using radio for the ‘last mile’. Winlink is one software application that provides the ability to compose, send, receive, and manage digital communications over an analog radio. It allows stations setup in shelters or other deployed locations to transmit formal messages or forms via email. Digital communications via amateur radio is a powerful tool for emergency communications.