Not just heart health, but a ton of other health - mental health, immune system function, respiratory health, etc. Pretty much all health outcomes improve with regular exercise and it’s by far one of the healthiest things a human can do.

If exercise was taught as something to make you mentally feel better and be stronger instead of be fit/look good/be skinny, we’d have a lot more physically active people. The former is easier to measure after each session instead of the time it takes to lose weight and look fit.