What allowed the Himalaya to become so high?

Question

Of course the mountains were caused by moving tectonic plates. But in case of the Himalaya mountains was the speed of the plates just higher so more energy got 'into' the mountains. Or was the continental plates just slightly more loose on the plates? Or did the plates just submerge more, if so what caused that? Or....

Answer 1

Two reasons for this are that the Himalayas are relatively young compared to other mountain ranges and the lower parts of Mount Everest are composes of harder rock For these reasons, the Himalayas have not eroded as much as other mountain ranges.