Kind of a silly question. Tons of games make use of the d-pad as buttons. You might hit them less frequently but it's still something you need to do from time to time. It's actually kind of beside the point anyways and not necessary for relating to this.

Even if you change the subject to the four commonly used buttons on a controller, we can acknowledge requires some dexterity to manage to hit some of them while also using the right joystick. We all more or less struggle with this to some extent but we have the ability to adapt in ways that others can't. You almost certainly take it for granted that whenever you need to use a button while also using both joysticks that you get creative in finding ways to contort your hands/fingers in all sorts of ways.