The problem with many rubber dome keyboards (but not all) is that pressing a key with enough force for the dome to buckle is not sufficient to reliably actuate the key.. to avoid missed keypresses it’s necessary to really mash the keys down all the way hard.
From what I understand, the most damaging part of typing is the impact at the bottom of a keystroke. When you use more force than necessary to press the key, every keystroke becomes a shock to your finger. Imagine you hold your wrist still (so that your arm isn’t taking any of the load) and then repeatedly whack your finger against a table: typing with excessive force is basically the same thing.
