I live in Los Angeles. Waze only learns a new route if you teach it a route. One time I was stuck in the hills in the Valley and traffic was particularly awful. It kept re-routing, and I was wondering why it wasn't sending me on a particular route, so I decided to go that way. Well, next day the route is full of people. This has happened a few times.

So now I have routes that I know and purposely do not share with any of these apps. I make everyone in the car turn off Waze, Google, etc. If I am in an Uber or Lyft, I will just sit there. I once shared a route with an Uber driver and it's now filled with Wazers. I also have routes where I ignore the no turn signs but Waze respects those so I don't care.