Not sure on the property tax situation in SV, but a common assumption is 1% of the houses's value annually. So with that considered, it is probably close to a wash with the S&P 500. And whatever upkeep as well, as you said.

Because of Prop 13 tax increase year to year is limited to inflation or 2% increase (whichever is lower). So yes, you start with ~1% of the house value but with 7% average increase in property value and limited to 2% increase in tax value you end up banking most of that property value increase.

But also don't forget to subtract rent (the value of actually living in and enjoying the house or one of equivalent value). It'll probably work out to the same or a slightly higher ROI