Of course rental affordability is not tied to asset pricing. Simply put it's tied to opex + cost of capital. And is opportunity costed against other investment

Of course rental affordability is not tied to asset pricing. Simply put it's tied to opex + cost of capital. And is opportunity costed against other investments -- but keep in mind real estate has high exit costs (realtor). So you'd have to think you can do much better on another investment to sell (and drive the asset price down) for it to make any sense. The insight is that the cost of capital is roughly fixed at the time of purchase. If someone bought a place in 1970 they can price bid down to nearly nothing because that's their operating cost and the purchase price is only a fraction of landlords who bought recently. Supply and demand create the conditions where landlords either compete on price, choose to sell, or potentially declare bankruptcy.