Yes, when the replace sugary drinks in the diet.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4786736/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4135487/

Yes, fluid calories are the main reason for weight gains, sugary drinks, alcopops and lattes with more calories than a pizza. These enter the bloodstream very fast, cause blood sugar spikes, more hunger, and the average Joe has their glycogen stores pretty full at all times. 25 percent of the sugars, depending on genetics , are converted to fat in a caloric surplus state. The fats, if the glycogen stores are full, goes straight to the fat cells, there was a study where they laced food with radioactive substance traces to make it trackable. Lo and behold, the fat started to assimilate to the fat cell within minutes. Another important thing that most people are not aware of is that the body always metabolizes proteins, glucose and fats at the same time. The body likes to store glucose, but doesn't like to use it, unless it's hard physical work, like lifting weights. It defaults to using energy when sedatery, sleeping and in general.

This can be good and bad, the good is that the fat is used(external from food or internal from fat cells during a caloric deficit), the bad thing is, if you eat plenty of carbohydrates at all times and don't work out, most of the external fats consumed via meals will be stored as body fat.

Often people say but average Joe's can simply eat less. In theory, yes, but it's not practical, if your diet consists of 2000calories of beer and fries and you don't work out, you will not look the same as a person who eats 2000 calories, works out(or not, diet weighs more) and eats lean proteins , not too many carbs and a bit of fat.

The beer and fries guy will also suffer from hunger pangs non stop due to blood sugar volatility.

Why it wouldn't How replacing a high calorie drink by a low one does not create a decrease in caloric intake?

No, they stimulate insulin release and make people hungrier.

IF you could IN COMPLETE ISOLATION replace sugary drinks with sugar substitutes then it would lead to weight loss.

The number of people who can actual accomplish that is probably very small. The majority of people, particularly those with actual weight issues, are going to wind up hungrier and gaining weight through consumption of other calories. They are not diet drinks, they are ruin-your-diet-drinks.