It seems to me that Apple attempts to avoid the "invasive" use of deep learning, while Echo and Home utilize it aggressively. Perhaps this is why Siri is seemingly lagging behind Google Now.

Another example of this is Photos apps - Google Photos constantly calls back to the cloud and showers you with computer curated albums, auto-slideshows and "remixes", and automatically tag peoples' faces, while Apple Photos does its learning on-device and buries the "creepy" facial/background recognition features deep in its menus.