I homeschooled my son. Once when he was about 10 years old he wanted to ride a bus. So, we drove to the Carlsbad Mall and caught the 302 bus from there to the Vista Transit station and back. Quite an eye opening experience for him. He never asked to ride the bus again.
“He never asked to ride the bus again.”
That’s just it. Just like public school, the experience trains you to be aware of your surroundings. Not to have your guard down but to adapt to dangerous situations, idiot people and how to interact and communicate with stated personalities.
My cousin serves in South Korea near the DMZ. He was once told by a retired Green Beret that one of his “training” exercises was to take public transit from area A to area B. Area A to B were known dangerous black neighborhoods. If you are able to navigate through these areas he said, then you can navigate your way through the streets of Baghdad.