Not true. Excessive calories lead to fat gain, irrespective of where they come from.
This has been demonstrated in numerous PR stunts where people have got ripped eating nothing but fast food or lost significant amounts of weight eating nothing but cookies.
The reason many people report good fat loss results when switching to a lower carbohydrate diet is that they inadvertently consume fewer total calories.
Now, some people may legitimately feel better on a lower carb diet and that’s cool. They may also report greater feelings of satiety which help curb overall energy intake.
But carbs in-and-of themselves do not make you fat.