The diet industry sells one simple rule because people want easy answers. But lasting weight loss needs a whole approach that addresses multiple health factors, not just cutting carbs or counting calories.
The diet industry is literally built around the one thing they know that their market is exhausted and apathetic from trying to lose weight. So they need to make the weight loss plan seem as simple as possible. That's why every single diet is about one thing. It's don't eat carbs, don't eat for 16 hours. Just count your points, just track your calories. It's on and on, but it's always one thing. And in my opinion, you need a holistic, comprehensive approach to mastering your weight in order to get the results you're really looking for. And the good news is, when you start to approach it that way, it's a lot more comfortable.