I can see where you are coming from FF and its important when educating people who are starting out in fitness/ older people and unfit/ high bodyfat people. But like you say I am young, naturally very very lean and naturally fit. Every week day I'm in the gym sweating and panting busting my ass, as well as trying to be in tune to what my body needs.
Then you got guys like my grandad who smoked like a chimney, drank everyday, ate ridiculously fatty food everyday, and did 0 training never mind cardio. I know that seems like an extreme example but in real life that's how people live. The gym is a chore that most people can not be bothered to endure. Sure it may shave a few years off in the end but this sport it far from healthy anyway. I might not live to 85 like my grandparents, but will that be because I neglected specific cardio training when I was 21, or will it be because I spent most of my young life lifting heavy weights day after day taxing my system, force feeding myself a protein rich diet, take supplements for this and that, having to do normal everyday things overweight/ obese. I dunno but as always I'm
not saying do what I do, I just give my own experiences no bull