Well, the difference is just eat less does work. Calories in calories out is literally thermodynamics. We are an energy equation. We don't collect energy from the air or the sun either. If you cease to eat, you will starve. And of course if you do not want to just eat less, you can increase your burn rate. Once again going back to the energy equation. Actually bust your ass. A good intense run should make you feel like you are going to puke afterwards. You may in fact puke. A hard set on the weights should get your heart rate surging and prevent you from even formulating words.

The issue with these things isn't that they don't work. It's that people attempt them and do not go all the way. They go on a little diet in some ways but fail to account for all their daily calories from stuff like beverages or snacks, maybe they aren't weighing their food either and just assuming a lot with what they are eating. They try and work out but it looks like walking on a treadmill or moving some 5lb weights around, far from running until lactic acid stops you or lifting to failure.

I think there is a lot of misjudgement of how intense a workout really is or how a diet should look like. And that feeds into this idea that it will not work.

But, you can't argue against thermodynamics. We don't make energy from nowhere. We are bound by the same laws of physics as anything else. If you can't lose weight with how you are eating, then the answer is obvious why that is the case: you are still eating too much given your activity level.