> One of the amazing things of the current system, as simple as it is, is that it's predictable and doesn't require coordination.

In many cities, the exact opposite of that has been true in my experience. I’ve waited at bus/train stops only for it to be 20+ min late or never show up multiple times per week. The unpredictability makes it infeasible as a means of transportation to getting to work or anything time sensitive (e.g., sporting event or show downtown). This is a much bigger problem in smaller cities with rudimentary public transit, but I’ve also experienced it in larger cities like Philadelphia.