Let me guess, were your friends using an old school dedicated GPS unit with no data connectivity? The problem with those is that they can't take traffic congestion into account. Under ideal traffic conditions a trip from Ottawa to Collingwood is almost as fast going through the GTA as the more direct northern route. But throw one traffic jam in the mix and it changes the game completely. All the main smartphone based map apps use data to route drivers away from traffic jams. They also offer drivers multiple routes to choose from. Like for Ottawa to Collingwood, I'm getting three routes: one through the GTA, one through Peterborough, and one through Bancroft.You are so right! Just did a short motor trip between Ottawa and Georgian Bay. It was the tale of two cars both using GPS, both following two completely different routes and in our car, two GPS's basically arguing with each other since they wanted to follow different routes. At a T intersection, the GPS told us to go straight through. The other vehicle was routed through Toronto at rush hour and was delayed 3.5 hours. They were very upset. We used a map on the way home and it was a much more relaxing event-free trip without being redirected through Toronto or into the back woods. Give me a map anytime. I want to know where I am going. I don't trust GPS (I was once sent to the service entrance at Disney in Orlando with no way of finding the public entrance without a map), and then there is the possibility that they are too out of date to give proper directions anyways.
Avoiding traffic is what I often use GPS for within the GTA, even when I know where I'm going. The fastest route could be half a dozen different routes depending on traffic. While it's not perfect, the app can tell me the fastest way, tell me about accidents or unusual traffic, and offer alternatives. A paper map can't do that.