Popsie: The traditional tow truck (lifts the front end of the car being towed) is a dying breed. Flatbeds are becoming the standard.
That said, the traditional tow truck is a bit different. A 4,000lb travel trailer has maybe 400lbs resting on the rear axle of the tow vehicle. A tow truck that lifts the front wheels of a 4,000lb car has probably around 2,500lbs on the rear axle of the tow truck. A drastically different towing scenario.
Then again, I'm sure tow trucks are treated seperately due to the practicality of setting up a brake system.