Because we’re fucking stupid.
In neoliberalist capitalist systems health care it’s a business just like labor force produce wealth for the owner, the health of the workers is just another side of the business.
It’s not the only one, many countries have Jobs that offers good private health insurance, but all of them have free health care too, so you don’t need it to live, it’s just an improvment or luxury that the job offera. Like staying in a private room, going to private less crowded hospitals etc. But again, if we don’t have a job we still have a good enough free health care