In independent towing tests, a fully-loaded F150 Lightning Platinum with maxed-out towing capacity, which is inferior to the 3500 by a few hundred pounds, could not even go 100 miles. It also takes 1.5 hours to charge at 440V, 14 hours to charge at 220V. At best, you would spend equal amounts of time charging as towing, which would be absurd (assuming you can always find a 440V charger).
I rest my case. It's like saying you don't need a Core i7 for rendering because you can survive with a Core i3. Sometimes you need a Core i7 - and you'd like your Core i7 to not randomly go slower than a Pentium if it detects its drawing too much power, right?
Edit: Removed 7700 F-150 Lightning limit, that was base model.