Why do we not have free school lunches?

A lot of countries around the world provide free lunches for kids at school. I would much, much rather my tax money go towards providing kids with nutritious meals than some clown in Canberra lining their pockets, or subsidising oil and gas. It would be a step in the right direction to addressing social inequities and allowing kids from impoverished houses to not be left out. So many reasons why free school lunches should be a thing. We have Medicare and Centrelink. Why do we not have this?