Sorry, for not having spelled it out explicitly.

Maybe it's because I'm too deep into the subject, which makes me assume that everyone is on the same page.

Once we expand healthspan, lifespan almost inevitably expands, too. That's because health is defined along a spectrum of physiological function and the declining trajectory along that spectrum.

The relation to "looks" is possibly a subjective one, but one shared by a majority of people: a toned and trained physique has a more appealing look than a deconditioned one. So, that goes hand in hand with the combination of exercise and protein intake.