Didn't read all the above posts but here's my $.02
Had a US built travel trailer, I was fixing and replacing things pretty much constantly. You'll have to take my word at it, but I'm pretty meticulous with my stuff so I blame the manufacturer as opposed to the owner.
When looking for a replacement for long term travel, as in months at a time, I looked for and bought a Canadian made fiberglass trailer. You know, the fiberglass egg type, except mines a fifth wheel. Have had it 2 years, putting on roughly 20k miles. The only issue so far has been with the fridge, Dometics to name names, which I do not blame on the trailer manufacturer. Normal lifetime for these type of trailers is decades.
Granted these are niche market, but quality is out there.