If people are not getting rentals for the Airbnb, hence the revenue collapse, that means they don’t have the cash to pay the mortgage. So the house will have to

If people are not getting rentals for the Airbnb, hence the revenue collapse, that means they don’t have the cash to pay the mortgage. So the house will have to go to the market, and that will depress housing prices, and that will scare people, who will sell their houses, further decreasing prices.