The American healthcare system is responding to the incentives that are in place, and those incentives are designed (if not intended) to drive up costs.

Doctors can be sued for malpractice if they miss something, so they're incentivized to provide as much care as possible, regardless of cost.

Hospitals and other healthcare organizations are likewise incentivized to charge as much as they can, since the bills are passed on to insurance companies.

Insurance companies have every incentive to lower the bills they pay. They negotiate volume discounts with healthcare corporations, and the billing system that gets worked out between these large organizations has little connection to the actual cost of healthcare provided to consumers.

For most consumers, insurance coverage is connected to employment, so it's very difficult to shop around. It could mean leaving one job for another, just to get different health coverage.

Inefficiencies abound. We can do better, but there is not a simple solution to this.

You could probably eliminate a lot of these inefficiencies by eschewing any sense of morality or fairness and simply letting more people die. Society isn't quite ready for this level of dystopia, but it's the direction we're headed if we don't change course. Nationalizing the US healthcare system may be the best answer, but it is guaranteed to be enormously complicated, and not guaranteed to improve outcomes.