I guess, because taller mountains need a bigger/heavier base (Mnt Everest is only a few km over it’s base, stone is too brittle) and a too heavy base gets “liquid” on, or literally under the plate (it’s magma underneath).
Only guessing though.
But then there’s Himalaya and the whole mongolian ranges on the same plate…
Seeing it like that, we are beings of energy, existing on the thin skin of a ball of molten stone, revolving around a ball of fire.