Equal funding mandates don't address cost differentials, and poor people often live where key education-related costs are higher (e.g., the cost of getting good teachers to work there, as the areas are less attractive to live and farther to commute from places more attract to live.)

And some states, IIRC, don't even have equal funding mandates to start with.

I didn't even know some states have an equal funding mandate, where I live the rich kids go to schools that look like castles and the poor kids go to schools with holes in the ceilings.

Equal funding mandates, where they exist, often address operating funding, not capital costs.

Of course, infrastructure quality effects operating costs, so there is a source of inequality right there.

Interesting. My high school looked like a prison. No idea if it's true or not, but some students said the architect did both.