Wwhy do so many people waste hundreds on diet pills abd fads?

Ok so i buy a pre workout supplement called acg3 helps with energy a lot i workout everyday and diet and i am losing weight fine about 5 pounds a week healthyly to i've never never understood why people waste so much money all you gotta do is eat right exercise jus don't understand why people don't actually think about what there buying cuz most of it doesn't help