The wages of all the people working in health insurance don't appear as profit, but if you removed the industry all that money - and the rents - would be released. To recapitulate it's not just the profit, it's the entire sectors costs that you release by removing the need for that sector.

There would be incidental costs, like more unemployment, and possibly some more admin within the healthcare system; though from what I hear it would more probably reduce admin costs on the healthcare end too.