Even successful studies show how poorly dieting works

I tried many different diet types, keto hypetrain etc, eventually had me and my gf write down the calories of EVERYTHING I consume, used an onlinr calculator to determine my resting calorie consumption was 2500, and that if I ate 1000 calories less than this every day I would lose approximately 1kg a week. I've kept daily logs and weighed myself daily for a few months. The trend becomes quite clear ob larger time scales, results match predictions almost exactly. (short term fluctuations are misleading - daily fluctuations in weight is larger than the weekly change you wanna measure - but plot it, and you will be enlightened as I was - surprised to realise calories really matter no matter what diet you follow - but it is healthier or more sustainable to consume healthy calories - nontheless for weight loss - nr of calories cannot be overcame through any other aspect of dieting)

Pretty much everything reliant on individual action / willpower works this way.

Anyone who's ever competed in sports knows that bulking and cutting works.

Most people aren't going to do it because most people can't be arsed. It's not that deep.