You're kind of damned if you do, damned if you don't. If you save up an emergency fund instead of paying a downpayment then you're spending money on rent that you could have in retirement, and it's not like rent is consistently cheaper than mortgage payments anyway so if you can save up when renting you can save up when owning.
So the gamble is, do you spend 2 years saving up for 6 months of income as a buffer and send tens of thousands of dollars down the drain in the meantime, or do you roll the dice and hope nothing bad happens in the next 5 or so years? The people who end up in the best position will be those who take the second option, and most of the time it will work out.