Skyscrapers aren't that tall either. Burj Khalifa is only 830 meters tall, which is about half the distance from here to the neighborhood store.

At 21,000 meters, the U-2 didn't fly that high. That's only a half marathon, and many people can run that distance easily.

In other words, I fail to understand your point, even omitting the 7.9km/second sideways velocity for LEO.