The point is that the body adapts to burn more or fewer calories depending on how much you eat. Restricting calories can possibly have the side effect of just lowering your metabolism, rather than just losing weight.
Reduced metabolism when dieting is a thing, and it's also correlated to weight loss. Less weight, less base metabolic rate. Down to a point which is irrelevant.
If your metabolism goes down, so do the calories out. That's one of many reasons that counting the calories out is extremely difficult.