Correct.
Most Americans treat their RV's like automobiles-- put fuel in and use.
Most have no comprehension of the complexity of what they own and most really don't care.
Yes, that based on the many, many mechanical inspections I have done on coaches over the last two decades.
Finding one with complete maintenance records is a very rare occurrence. And, even then, they often have glaring omissions. Easy to find 15 year old DP's with no change or service of air dryer, regular automobile coolant in the cooling system, etc.
For every DP that is worn out, probably 20 times that number die from neglect.