The equities markets have been irrational for some time now, you can't compare to them. They're going up because there's so much money sloshing around in the global pool of liquid wealth (due to global wealth inequality, but that's a different discussion) that it's simply being willed up by the continued investments. The comparable RE market is superlux NYC tower apartments. There's no rational reason for $100m apartments except that someone will pay it to park their money somewhere, anywhere.
This is my 'elevator pitch' for rentals:
If you buy a rental property that does not cashflow ,but pays all it's bill and maintenance with 25% down on a 15 year note, at the end of 15 years you own it outright and have made about 9.6% annually CoC. In more rational times that would be considered phenomenal returns in equities over 15 years, Bernie Madoff territory. Now, pile on the fact that rents go up even if you weren't cashflowing from the start, values go up, and you can do some of the more elaborate refi and reinvest schemes upthread. It's hard to come up with something as safe AND as profitable.