Yes, the world is very aware of how to lose weight.

Turns out knowledge doesn't work very well, or rather loses efficacy in certain environments. Individuals can vary in their ability to regulate the hunger response signal they feel, which is stronger with higher weight (as your body now needs more calories to maintain its larger size).

GLP-1s don't appear to have such an efficacy loss and do work well. Sometimes with minimal to no side effects.

Your arrogance shows you don't understand population level weight gain, or the biology of weight loss difficulty. Obviously calorie deficits lead to weight loss. But that isn't the hard part. It never was.