How do you UPS drivers deliver so fast?

I am asking any deliver drivers that work for UPS how you manage to deliver your packages in a timely manner while still getting home in time. I read the average UPS driver has about 150-200 Stops. You guys carry heavy packages, stop to talk to people, pick up additional packages, drive a large truck, and also have to knock on peoples doors and wait for them to come and sign the package. The reason I ask this is because I work for Amazon delivery and I drive Mercedes Sprinter vans. I have about 115-150 stops per day. If its a mostly house route I can deliver 70 stops in 3 hours if I work really hard. We don't talk to people, or have heavy packages, nor do we need to pick up any additional packages, and we also leave the package at the door, knock and walk away. And this usually takes us 10 hours. I am thinking about working for FedEx or UPS so if anyone can tell him exactly how it works.