I don't know, I hear this advice all the time and I think people are just not looking hard enough. I invested in Seattle between 2017-2022 and have several properties here that are cash flowing.

For example, for an $800k house you would have to generally put down 160k. If you picked the right property, with enough rooms, you can cash flow around $1-2k on this which will net you around 10-20k a year, and that's not counting the tax advantage of depreciating the house which is substantial.

When you throw in the fact that the asset could/should appreciate, the fact that you can borrow against it, leverage aggressively to buy more—don't know, my reasoning could be wrong, but it doesn't seem to always be an inferior investment vehicle.