Everest is littered with dead bodies that have never been recovered.
Yup, human bodies and fecal matter with oxygen canisters thrown in for effect. Everest is one giant shitpop waiting to thaw.
Including that of George Mallory. In fact, climbers on the North Face used to use one body ("Green Boots") as a landmark. "Turn left at the body with the green boots and go on to the Second Step."
Everest, as any climber will tell you, is NOT a particularly challenging climb technically. It is an extremely harsh hike though. Today, a lot of people with more money than brains or training are attempting to summit, with traffic jams along parts of the route that cause fatal delays.