Health insurance is not about getting somebody else (eg. the government) to pay your medical bills. It is about risk management. When you have it, you don't have to worry that you won't be able to afford the care you need.

The people who could get but don't are the same people who think they will win the lottery. Young people who think they are immortal. Older people who think they are in good health now, so they should continue to stay in good health. But we all die eventually, and almost none of us will be in good health and suddenly drop dead. That's like winning the lottery! Nice if it happens but don't plan your retirement around it. The house always wins.

Most people are lousy at risk management. We worry about things less likely than being hit by lightning twice and ignore likely causes of death or injury. It is so uncommon a skill that insurance companies have highly-trained actuaries who do nothing else but calculate the real odds of something bad happening to you. Yet another reason to pay for insurance: They know stuff you don't. Smart people recognize skills they don't have and hire an expert.