RVs are junk because a majority of buyers want the sizzle not the steak and they want it at the lowest possible price.
Just look at some campers; island kitchen, fireplace, fancy faucet, and LED lighting on everything. Most buyers are so starry eyed over the bling they don't care about the piss poor engineering, shoddy materials, and assembly methods that are a complete joke.
When the buying public is ready to spend on proper engineering, quality materials, and detailed assembly then the industry will change.
There are quality campers out there but most are expensive and therefore remain somewhat niche.