The towing ratings on EV trucks is just on how much weight it can tow, it doesn't list the distance.
Gas trucks of course also take a hit, things can very based on trim model, how one drives, type of traffic or constant speed etc. But a gas 2023 F-150 is rated at 24mpg for highway, but drops to 14mpg towing. The average smaller gas tank is 23 gal, so on a full tank you can get around 322 miles of towing, and be able to spend 10 mins to refuel and keep going.
That's over 4x the towing range of the Lightning. Heck the non-towing range of the Lightning is 300 miles, which is about 55% of the range of a gas that can get 550 miles not towing.
Just because Bob's Rickshaw is green only needing to fuel Bob and can get you five blocks in the city, it doesn't mean you'll want to use him for a cross country drive.