It's usually the weight of my whole hand. I touch type, but my hands are usually tilted to the exterior. So I hit keys like Enter, Capslock, Shift, with the side instead of the tip of my fingers. And I don't mind sliding my whole hands if I'm going to use it repeatedly.
Side vs tip doesn't come close to tipping the balance
And the last part is backwards - you don't need to use it repeatedly, there are much better alternatives, so you could just as well not mind not doing it
