Beyond the risk of medical bankruptcy in the US, lack of health insurance can prevent you from getting some lifesaving treatments.

If you are uninsured, for instance, you stand almost no chance of getting an organ transplant. There are not enough organs for too many people, the operation is very expensive, and lifetime support medication is also expensive.

In my experience, transplant centers won't even start the evaluation without proof of insurance.

While it might be possible to get insurance after diagnosis for people like the OP who choose not to have insurance, that isn't always feasible. Sudden organ failure, while rare, certainly happens. And should it happen, it is hardly the best time to be scrambling to find insurance.

Yes, the system is screwed up. But it is the system (in the US).