That might be true if, and only if Waze has correct edited data for EVERY segment of EVERY route, which it doesn't. Waze thinks roads are one-way if they have only been driven in one direction. It has phantom turn restrictions. There are numerous unconnected segments it has to bypass by routing around. Until it has totally correct maps with exactly correct segments, I DO know better than it does. Just driving around doesn't fix all the map problems in Waze - they all have to be hand edited and until that happens, I want to have it learn as many alternative routes as possible. The more alternate routes it knows about, the better it will know which way is the best at any given moment.
Not only that, but I also know better than Waze when it comes to things like construction zones. There's no way to make it understand that road construction takes longer than a few hours. I also know about things like traffic density changes based on time of day, temporary road closures for things like parades, VIP motorcades, races, or street carnivals. I know my routes better than any GPS, and I always will. I win, not Waze.
...when you care enough to Waze the very best