I use Waze all the time. It's not the greatest thing since sliced bread, but once you learn how to use it and set it for your style it's great at what it does. Waze, though owned by Google now is a separate division, Google bought it but from what I've read there is no plan to merge Waze with Google Maps and eliminate one or the other.
On a large interstate with plenty of room for a car on the side of the road the warnings might be overkill, but on a 2 lane road they are invaluable. Same with knowing where the cops are, gives me time to slow down or move over a lane.
As for rerouting, it's not fool proof. But it does work. I've been rerouted around my own community when an off ramp was closed. While in LA a few weeks ago it offered several solutions.
It's just a tool, driver is still in charge.