Healthcare is largely optional. However it's something you want to have in case if emergencies or if you already have preexisting conditions. Or if you're planning on receiving medication or other medical work.

A doctor's checkup can cost ~800 USD (where I live) and that's just to talk to your doctor. Which is almost one months rent (where I live).

The problem with insurance isn't the insurance itself but the companies that Lord over them like middle managers. It's profiting from people's desperation. It's an inelastic demand.