I found the shortage of fifth wheels to be very strange as I would think that a fifth wheel would be the RV of choice.
With a motor home, you either have to pull a car or resign your self to the confinement of a camp ground. Plus, you have an investment of a motor and drive train which can only be used for travel. So, unless you are traveling continuously, your investment will sit idle.
With a travel trailer, you can leave the trailer in the camp ground and drive your truck to destinations. And, when you are not traveling, you can use your truck for other purposes. But, the conventional trailer hitch leaves a lot to be desired.
With a fifth wheel, you get the best of both worlds. You have a truck that can be used 365 days a year even when you are not traveling and you have a better hitch arrangement. So, why there are not more fifth wheels on the road is a mystery to me.
very good point I had not thought of – but I still think the original poster was closer to the answer..