The cost of living varies widely in different areas. In many parts of the United States, 100k is a very low salary, due to extremely high living costs.

For example, the government classifies a family of four with an income of $149,100 as "low income" in San Francisco, and thus eligible for government welfare benefits.[1]

The median house price in San Francisco is currently $1.3 million.[2]

An average 776 square foot apartment (which is rather small for a family of four) rents for $3,336 a month.[3]

[1] https://www.hcd.ca.gov/sites/default/files/docs/grants-and-f...

[2] https://www.redfin.com/city/17151/CA/San-Francisco/housing-m...

[3] https://www.rentcafe.com/average-rent-market-trends/us/ca/sa...