I think the condo can be well-made too, just that it costs a lot of money to do that. What I think is happening is the flashy, veneered condo is selling for a price point that would be inhabited by a smaller and more utilitarian RV built at high quality level.
I think some of your best built trailers are Casita and similar. Of course that won't suit everyone due to small size. Livin Lite makes some interesting aluminum trailers. For many people RVing is just one of many recreation activites they engage in. They could consider that they may not need a condo, that a smaller, easier to maintain RV would pay off in benefits even if they are cramped for space or have to adjust.