I did a few experiments between Google, Apple, and Waze about their ability to reroute. I used Nixle to let me know when a major intersection closed. I would then put in a route that would take you through that intersection, and then see how long it takes each app to reroute.
I usually find that Apple Maps is the quickest to reroute. Within ten minutes, Apple Maps is rerouting you around the closed intersection. Google maps usually takes about twenty minutes and a few times, it would reroute you off the street, down a side street, and back to the closed intersection before finally choosing a route around the intersection. Neither seemed to mark the intersection as closed, but they detected the traffic buildup and rerouted.
Waze was a total disappointment. In my experiments, Waze never rerouted traffic. I live in the burbs, and that might be the issue. Waze depends upon user reports. Not that many users, not that many reports.
Both Apple and Google rely on the phone position data. Both can detect if someone is driving and when traffic slows down and is rerouted upon side streets. I’m not sure why Apple is usually faster. Maybe most iPhones are set to give Apple location data and most Android phones aren’t.