Strength training combined with diet is better than cardio and diet. And before someone says it, it, I don't advocate doing both strength training and cardio.
I don't think most lifelong natural athletes are described as having "massive bodies." I use the term strength training synonymously with resistance training, which differentiates it from, say, cardio. It need not be powerlifting to be strength or resistance training. Here's a thought-provoking article on resistance training and cardio I've posted in the past that you may find interesting: https://www.cbass.com/NoCardio.htm That's not to say I don't do any cardio. But I limit my workout cardio to brief ~HIIT. I'm not suggesting that's necessarily the best way to go, but it appeals to me.
Once again HIIT...they say it impressively improves Vo2 but is it better than steady state cardio for an hour on the CV system?? personally I doubt it ...TUL ie time under load has benefits that extremely brief high-intensity can't replicate, I believe. I have no hard evidence to support just a feeling. They are different, and physiological effects or results are different too. Steady state cardio being better. (I do one hr TM 6/days/week. about 10 K/WO) There is also the danger of running up the heart rate toward to maximum with HIIT.