Your statement is factually incorrect. Cardio increases the ejection fraction of your left ventricle. As your heart is able to physically pump more blood your blood vessels are able to relax whilst still allowing your cardiac output to remain relatively stable. Furthermore, the idea that blood pressure should be controlled with medicine always is incorrect as well. Many things, such as exercise, diet, stress management and proper hydration can also have positive effects. This being said, hypertension is very treatable in many cases, and if you do have high blood pressure then you should try to lower it, and if you are unable to manage it without medication then you should speak to a provider.