My first RV, a '79 class C Roll-a-Long purchased at 10 years of age, was used by me for 10 years with no issues other than the roof AC needing to be replaced about 7 years after we bought. That means that it lasted 17 years, and all of the other appliances were still going strong at 20 years of age when we sold it. The next RV was a '89 class C Jamboree also purchased at 10 years of age. Used that one for 15 years without a single appliance or house related failure other than a furnace control board. Had to rebuild the transmission, and repair the dash AC during it's tenure with us, but nothing more. I'm hopeful that my current '04 class A Itasca (purchased at 12 years of age) will be as dependable, but I do wonder.
A big part of the equation, I think, is the "throw-away" mindset of almost all products manufactured today. How long is the expected lifespan of a roof AC today vs 20 years ago? Certainly not the 17+ years I got out of my first and second, even though the units look and perform pretty much exactly the same, and are tasked with exactly the same job. We recently purchased a new washer & dryer (Maytag, for the S&B house). After just 2 years, the transmission on the washer went out. This didn't even surprise the repair guy; he said it's common! Really? My last washer lasted 15 years, and was STILL going when I bought this new one! So while the internet has indeed allowed access to more stories of failure, I do believe that the failure rate is indeed increasing, at least on major appliances and components. Add of course the ever increasing complexity of many of those components just adds to the problem, as does the requirement for RV manufacturers to knock out as many RVs as possible in as short a time as possible.