@Kai Van Leuven
I have thought about these same issues as well (especially stagnant income growth effecting appreciation).
This is a real thing and it seems income growth has stagnated for quite awhile for a lot of folks.
My input would be that, as others have pointed out, people will always need a place to live. There may be an overhaul of "the system" at some point (topic for a different thread haha) but as long as you haven't overbought on properties with zero cash flow in ND at the height of the fracking boom, you'll more than likely be fine.
Chances are, people will always want to live 🎶downtown🎶 and the folks that currently are are already paying thousands per month for a shoebox. I'd be willing to bet that gentrification continues in coastal areas and becomes even more exclusive than now. At some point there will need to be more vouchers and such in place so that the workers at the bottom will be able to live in these places to support the economy.