Apple didn’t invent the smart phone, they just took the idea of a smartphone and jumped ahead a quantum leap. It’s a bit too much to say they perfected it, but they laid down the basic parameters of what an early 21st century mobile computing device should have: touch screen, gestural interface, camera, wifi, app store, and so on.
The idea of people-first email is also not new. I have tried a number of email apps that are organized around the identities of the senders and recipients of email, instead of the default time-based queue of messages. For example, Hop, which is positioned as ’email at the speed of life’. But I am still waiting for someone to do it right.