In my experience, the problem was long wait times between buses and unreliable pickup times. That meant you realistically had to add buffer at each end of your trip: in case the bus was early and in case the bus was late. Not only was that more than 20% of my trip time, it was also mental overhead of worrying whether you already missed the bus.
The bus might come 2x per hour. Maybe 2:18 and 2:48. But it might come at 2:15 or 2:25. So you need to arrive at 2:13 and possibly wait 12 minutes. Or if you arrive late you might be waiting 30+ minutes.
The bus might come 2x per hour. Maybe 2:18 and 2:48. But it might come at 2:15 or 2:25. So you need to arrive at 2:13 and possibly wait 12 minutes. Or if you arrive late you might be waiting 30+ minutes.
Make the buses fast and safe.