Because in a country like the US where half the population is obese, the biggest health marker they need to improve is body fat percentage, and there's no easy

Because in a country like the US where half the population is obese, the biggest health marker they need to improve is body fat percentage, and there's no easy way to measure that accurately and directly, the most convenient proxy is weight. I enjoy strength training and would recommend it to anyone, I've put on roughly 25 lbs of muscle in the last ~18 months. Realistically however it's very easy to put on fat as well when you're going for gains. If you're a typical American fatty who's sitting at 40% body fat you're probably out of shape, you probably don't know how to lift with good form, you don't know what a good routine looks like, you're probably prone to injury if you push it too fast, the thing to focus on today is probably to clean up the worst offenders in your dietary habits and lose a few pounds. Weight lifting in my opinion would be #2 after that for immense and varied benefits but it's a slower burn.