The intuition is correct and the article mentions it, purely taking a diet and replacing sugar with sweetener will help. It's just that in the real world people

The intuition is correct and the article mentions it, purely taking a diet and replacing sugar with sweetener will help. It's just that in the real world people don't often make such pure diet changes, so what people are often asking is 'Does the average person who tries to consume artificial sweetener over sugar successfully lose weight?'. The answer to that appears to be: Not really. Why? Is it to do with the sweetener itself? Or is it just with food labelling? Or marketing? Much harder question.