While exercise is extremely important for maintaining a healthy heart, it will not be much use if you want to lose weight:
https://www.vox.com/2018/1/3/16845438/exercise-weight-loss-myth-burn-calories
The most reliable way to lose weight is to eat below your base metabolic rate each day for a prolonged period of time.
As such, it's not really a question of exercise. It's a question of diet. That's not entirely down to education (although that is by no means insignificant). Most people know what they are eating isn't healthy and that they eat too much of it. Most people who are fat know that they are fat, and decide on some level that they would rather be fat than diet. A lot of this has to do with marketing and the fact that we live in an extremely consumerist culture - if everyone else is fat, why should you worry about it?. In addition, there are far too many people who profit from other people over-eating (and eating badly) for this problem to simply be defeated by education.
I don't know what the solution is. It's a fairly unprecedented problem in human society. Maybe there isn't a solution and we just have to put up with the obese west getting steadily fatter and fatter for eternity.