Because sweating a lot only loses water, and burning fat is the most effective way to reduce fat, there is no particularly important connection between them. Insisting on exercise and ensuring exercise time is the key to burning fat.
For example, a marathon runner can easily lose a few pounds after running a full marathon, but this is only because sweating leads to a decrease in water in the body, and most of the weight lost can be recovered through rest and hydration.
Therefore, the effect of sweating fitness clothes is not as obvious as advertised.