If you take a look at your local gym, you will see about half of the gym likes to lift weights (without any cardio) and the other half seems to do cardio, but without any weight lifting to supplement it. In reality, they are both important and can both serve a purpose in achieving your physique goal. If cardio is implemented on a regular basis post-weight training, then the person will gain all of its benefits; increases energy, better mood, higher metabolism, leaner physique and more! At the same time, however, it should not replace weight training altogether unless that is the goal or if that is what bring you satisfaction. Training should be rewarding and enjoyable and should enhance your life rather than making it more difficult. Overall, cardio is great for everyone and can serve as a tool that can be used to become an overall healthier person (despite the goal, cardio can help everyone if used in moderation).