It's not technically impressive and odd they would be getting it wrong. They know where your hits are coming from and the WiFi/GPS information on mobile. If a Maps app can it get right 100% of the time why can't Google ?
GPS location is, agreed, not technically impressive. but successfully leveraging location history alongside of real time traffic data to intuit home and work addresses and the drive times between them with zero user input and an acceptably high level of accuracy seems somewhat impressive here.