https://www.zillow.com/homes/recently_sold/house_type/
In the South Bay near Mountain View, there's basically no single-family homes under $1.5M, and the majority of houses go for $2M up. Many are in the $4M+ range. You can get cheaper in San Jose ($800K-ish for a run-down 2BR from the 50s) or Daly City (low millions), but most of the Peninsula and SF has a floor at a million.
Most Bay Area residents just don't own homes. They rent permanently or maybe own a condo. But the context for this sub-thread is "people with a house", and basically all mortgages for single-family homes are jumbo if you're not paying in cash or putting >50% down.
Buying a house for $1M is firmly middle class status. True lower class people simply cannot afford to live in the Bay at all.
To be in the top 1% in the Bay Area you have to make close $1M per year.
https://www.cnbc.com/2017/06/14/how-much-you-have-to-earn-to...
A 40% ratio for the $125,000 household would give you a maximum purchase price of $830,000, which would be a conforming loan in the Bay Area, not a jumbo one.