Not a single word you have said contradicts anything I've said. There are indeed many studies where you can show if people reduce calories for 4 to 12 weeks (usually in controlled lab study settings) they will lose weight. That is quite simply not in dispute.

But there are also many studies now that demonstrate what happens when you try to apply that insight to the real world. And what is fairly consistently observed is that people who reduce calories will lose some weight for the first 3 to 6 months. But when you come back to the 2+ years later they are back to their initial weights. Because, as I already noted, people find it incredibly hard to maintain dietary changes. Whether you want to refer to these as diets or not is somewhat moot, you're advocating a dietary change (i.e. reducing calories) as means to control weight, I don't really care if you want to label it some other way.

And much the same applies to exercise, in controlled lab settings with fixed calorie diets given to participants you can definitely show that people will lose weight with exercise. But in the real world what you see is that people slightly up their calorie intake in the hours after they've exercised.