A weight distribution hitch when used with sway control can help prevent trailer swaying which can be dangerous.
The weight distribution hitch also helps to level out the vehicle to keep the front wheels of the vehicle on the road so you have better control over your steering.
Weight distribution hitches do not help you tow more than your vehicles rated capacity but it does help with leveling the trailer weight out and prevent vehicle sag and helps give you a safer towing and ride with your trailer.