The function of a WD Hitch is to "distribute weight". You drop your TT on the hitch and the weight on the back axle increases. The back of the TV goes down, the front of the TV goes up.
When this happens, rear axle weight increases and front axle weight decreases, this is no big deal until you add enough weight to effect steering and braking on the front end.
The WD Hitch torsion bars push up against the tongue weight and redistribute the weight to the front axle and the TT axle to restore some of the steering and breaking control.
My F-150 barely notices my pop up but sags when the TT is added.
It is your choice but you will notice when you need one.
Good luck