"Slate" is an old highly woke online magazine. Easy to dismiss. However, they have begun a series on fitness and health that might be good, or at least rational: Fitness goals for 2023.
For example, they make the point that exercise is, generally, useless for weight loss. Weight is nutritional - period. There surely are genetic effects on body architecture and maybe even on satiety-signalling.
Is exercise useful for cognitive functioning? Dubious.
Also, the point that the current thing about "lots of fruits and vegetables" is nonsense. Food is not medicine. Nothing wrong about those things though as long as you do not think of them as magic.
Fitness goals, I agree, are primarily about feeling good, maintaining functionality and vitality, and looking good for as long as possible. Those make life better. 6+ hours/week is good.
I stand by the Maggie's Fitness for Life program: Weights, calisthenics, and cardio. With a little luck, it might slow your fate in a wheelchair.