For more than a century, surgeons have routinely worn masks while operating, primarily to protect their patients from air or droplet borne infection.
Imagine going to a surgeon's office to discuss an upcoming procedure. Your surgeon informs you that his libertarian beliefs have led him to abandon the wearing of a mask during surgery. If you have common sense, you will promptly leave and look for a surgeon who cares about your well-being.
Wearing masks in stores and other public places is chiefly about the well-being of those around you. When you care more about your individual liberty than the health of others, you are giving liberty a bad name.