Recently at the American Museum of Natural History in New York, I saw a display set that claimed erosion makes mountains rise higher, counterintuitively. The explanation was that the material removed from a mountain due to erosion makes it much lighter. Since the mountain sits on a landmass that is floating atop magma, a lighter landmass rises higher. (Similarly, boats rise higher in water when weight is removed from them.)
I have been looking for resources online to confirm this, but none mention it. They tend to claim that pressure due to shifting tectonic plates is the cause of mountain growth, and if they mention erosion at all, they only discuss it as a possible shrinking factor.
What do actual geologists have to say about this? Does it depend on the mountain range?