The more weight you put on the back of your tow vehicle (tongue weight) behind the rear axle the more weight is removed from your front axle. In an extreme case your front axle will come off the ground.
That obviously won't happen with a travel trailer attached but it does remove a significant amount of weight.
Less weight on your steer axle means you have less control of your vehicle. In addition to that 70% or so of your braking force comes from your front wheels. In a panic breaking situation the trailer tongue will be diving and removing more weight from your front axles to the point that they may loose traction.
In normal driving on nice dry roads this is not usually an issue but for wet and slippery conditions it could cause lots of trouble for you and other motorists on the road.
A weight distribution hitch's primary goal is not to level your tow vehicle or trailer it is to restore all or most of the weight lost back to the front axle of the tow vehicle.
Air bags or sway control do nothing for either of those safety issues.
2014 Jayco Swift 281BHS
2015 F250 XLT 4x4 Crew Cab, Short box, 6.2 gas
Solar powered! The trailer not the truck!