For me, my body fat comes from my diet. I have never been overweight, but always had a "female" softness to me. It wasn't until I went exclusively whole plants (with no overt fats) that my body fat effortlessly went down. I did not change anything about my workouts (I have always done a nice mixture of cardio and weights and stretch).
It was the heavy lifting that gave me the "cut" and definition. The fact my diet made me lose any extra body fat showcased the fact I had been heavy lifting...which has given me quite the cut and lean physique. And the heavy lifting gave me a "power" that is kind of hard to describe.
For me, cardio helps tremendously with my stamina, health, heart, lung function; but in no way touched my weight.