Less mass beneath my feet? That depends very much on how you measure "beneath", right? I'd argue that if your load is being distributed into something, it's beneath you. If I'm standing on a mountain which is sufficiently sharply pointed, then almost the entire mountain might be engaged in supporting my weight — cue fat jokes. But anything it's standing on is going to be the same thing, so wouldn't that make it more mass "beneath" my feet?
Anyway, I RTFA (my geek card is in the mail, it should be back at the processing facility shortly) and the article is all gushily excited that "thereâ(TM)s far more crust underneath the mountains than there is in the oceans!" Wait, was this a surprise to anyone? Mountains happen when earth gets shoved up into the air. They're not pimples.
So in short, the article comes to completely the opposite conclusion of the truth: they say that "if you wanted the least amount of mass beneath your feet, youâ(TM)d climb up to the peak of the highest mountain" when in fact, there is more mass beneath your feet if you stand on a mountain than if you stand on the seabed or in a valley, because of all the mass that by definition can't be beneath your feet if you're standing at a lower altitude.