If a service technician has to replace it he has to cut it to fit and probably put down quarter round along all the edges. Work that took 15 minutes in the factory becomes a two man, two day job for service. Lots of interesting things happen during transport. Drivers are paid by the mile so they like to make time. During transport the bumps, vibration, and other forces twist and torque the homes and frequently crack panels, loosen connections etc.
Drivers occasionally rub against traffic signs etc.
Mobile home tires are inflated to 2.5 times the usual pressure so blowouts are not uncommon. If a couple of tires go at once and the frame hits the ground it can be bent making future leveling impossible. Setup can raise difficult issues because of the number of organizations involved. The factory is responsible for the home itself, the dealer is responsible for making sure the home was ordered properly and any optional features are installed properly, the setup company is responsible for setting and leveling the home, and hooking up the water, gas and electricity. If air-conditioning is needed that is probably done by another company.