All in all it is just a "marketing" scheme...
I have a "Ultra Light" Travel Trailer that I have over 40000 miles on in 7 years and close to 600 nights of use in also...
After the 1st fix of the shower p-trap not being connected correctly from factory
I have never had any issues at all
No cabinets loose ever
No feet through the floor
No issues at all
The only thing I do is keep it clean, Keep up with the maintenance on the roof seals seems etc and repack the wheel bearings yearly
I have seen on these forums over the years people paying 60 - 100g for thier so called top of the line rigs and have many many many costly issues with them.
Honestly its just the luck of the draw you either get a good one, an ok one, or a bad one...all depends on the technicians building the rigs mood that day...