California has a high poverty rate as measured by local cost of living (but very low using the standard federal methodology) 8j no small part because federal funding formulas funnel money out of California because of its aggregate economic success, limiting it's ability to effect distribution.

The fact that the federal government has used the income tax to centralize power, taking money from the citizens of the states and sending (some of) it back with strings attached, is a different issue.

Regardless, the cost of living is the cost of living.

Poverty is a definitional thing, it does not refer to actual living conditions. Poverty in California and poverty in, say, your average red state are very different. Our people in poverty have access to a wide range of public benefits. Our poverty line is quite high which means people qualify for public benefits at higher levels of income. Living in California in poverty is far more tolerable than living elsewhere in poverty. Likewise how being in poverty in the USA is nothing like being in poverty in India or even China.