FWIW, when the dot com crash happened and tons of people were out of jobs, it didn't kill prices.
Downturns have typically resulted in flat growth of prices, but only the foreclosure crisis managed to push houses serious negative. And typically existing rents don't go down, instead you have to move to get a better rent deal.
Over a long enough window the expected value is that you'll get back your principle. Which is more than you can say for renting. "Worst case" is you end up walking away with nothing because the mortgage is underwater.
The only outcome of renting is you walk away with nothing when you move.