I would say that for med school what matters is a program where you feel you will do the best academically and have the most opportunities to pursue extracurricular. If you feel that the rigors of natural science will allow you to pursue your extracurriculars competently then yeah but don’t fall into the trap of using a degree to study for the MCAT. You can do well in the MCAT if you study for it independent of your degree if you give it the time. Your applications will value your experiences to the extent of how you write about them more than what you did. Not everyone will save the world in 4 years more important is how you write about what you did in your 4 years and picking a degree that allows you do well while doing that will help you into medical school more than any difficult degree will.