Why do people move so slowly at the top of Mount Everest?

The higher you go the less oxygen in the air you encounter. In case you get the chance to drive for example to a 15.000 feet pass in Colorado you can experience that for yourself. As soon as you get out of the car and try to climb a short slope you might feel out of breath very fast. So mt. Everest is almost twice as high! On top of that all their equipment and boots (the weight of them ) does not make it easier. On top of that often time there is a fierce wind up there as there are no mountains aroung to stop it. And also often times they have to deal with mountain sickness to a certain degree and last but not least they might have several hours of climbing behind them so with all those hard conditions it might be understandable that they do not run around llike a jack rabbit!

You go up there and do wind sprints, see how you feel. They’re damn near in outer space...

The lack of oxygen and the multiple layers of clothing that they have to wear in order to not get hypothermia.

Because it's strenous. They have to carry oxygen with them when they go due to the very thin air.

they might just be trying to be careful about not falling

Most people have severe diarrhea at that altitude.  This is a little known fact. People are walking slowly because they are clenching their butt cheeks together.

Very little oxygen in the air to breath, if they tried to go faster, they would collapse.

🥴

Jet lag? Charlie horse?