Why is the government still bothering with such a variable quantity like household income, why not per capita? Household income introduces unnecessary complexit

Why is the government still bothering with such a variable quantity like household income, why not per capita? Household income introduces unnecessary complexity with how family sizes change over the decades, between ethnicity, by divorce, and all sorts of other confounding factors. https://www.creators.com/read/thomas-sowell/09/16/misleading-statistics https://www.creators.com/read/thomas-sowell/09/16/misleading...