Canada had a wonderful mass transit system when the vast majority of the population lived rurally. But the urbanization movement saw people move to where the high density allowed one to walk everywhere, so there wasn't much need for the mass transit anymore and eventually it was shut down.

Cars have driven cities to become woefully less dense than they used to be, which is why you see value in a return of mass transit. When you have rural problems (life being too far away to walk to), you need rural solutions. But isn't the even better solution to get the idea of cities being wannabe rural areas out of our heads completely and start densifying again?