Market facts. sooner or later. Every one that wants a RV will have one. Yes people will trade up, and there will be a few new users. But is has to top out somewhere. Just like trucks, and cars. They too are toping out. RVs last longer, as do vehicles. And something else to think about. Many younger, and first timers are finding it less expensive to buy a MotorHome, rather than a truck, and TT. Most mid range MHs are less expensive than a TV, and TT combined.
As for me. I HOPE to have bought not only the last TT I will ever have, but the last Truck, and car as well.