Earlier quoted context omitted.
I’m guessing this is sarcasm, and yes, it’s not a sure thing, but it’s pretty close. Also, you have to live somewhere so the investment is offset by the rent you’d otherwise be paying.
Owning is more expensive renting generally in the Bay Area. You’ll come out ahead owning if you own for 5-10 years and see appreciation. But SF housing dropped 30% in 2008. No reason it can’t happen again.
And yes, you need a ten year time horizon for the risk to be small. By 2014 the SF home prices were above the peak in 2007.