Yes, it saves our time:
1. We don't have to go to places to deliver our important files and media
2. People can watch email if they missed voice call in their preferable time
3. We can send many emails at once to many people which saves lot of time
4. Email can be categorized to find important emails like job applications or friends email etc
5. We can search for emails and view it later when we need it
6. Some email features like quick massage saves a lot of time for conversation
7. Can send email to far away places where moving might be way too difficult