Not arguing that housing is expensive, just that "There is no amount of money an owner could pay an employee within the economics of a small business" is an extremely broad claim and obviously wrong.
High-paying small businesses, especially when employees do not have children to support, do fine. It's not like you see mass retail vacancy in SF.
Here you go: https://techcrunch.com/2014/04/14/sf-housing/
All the numbers and data have gotten worse in 2014.
Oh yeah, and SF's onerous rules are making it even harder to expand the housing supply: https://www.bizjournals.com/sanfrancisco/news/2018/12/19/hou...