The killing of UnitedHealthcare boss Brian Thompson has sparked widespread reflection on the frustrations of navigating America's healthcare system. Many have shared stories of insurance denials and the devastating financial and emotional toll these have taken on families.

Every country aims to control medical costs, and many wealthy nations -- Switzerland, for example -- also rely on private insurers to help manage care. What sets America apart is its patchwork system that pits loosely regulated, profit-driven players against each other. The result: enormous administrative waste, uncertainty for patients and little added value.

The U.S. spends almost twice as much as comparable wealthy countries, including those with private insurers, on healthcare. Cracking down on insurance companies can only go so far in rectifying the disparity. That is because the bulk of America's health bill stems from the high cost of hospital services, drugs and care in general. Even if we were to eliminate insurer profits, we wouldn't make much of a dent in the high cost of U.S. healthcare. But that doesn't mean the insurance system can't work better.

The roots of today's fragmented system can be traced back to a quirk in U.S. history. Unlike most high-income countries, which created centralized government systems to ration care in the 20th century, the U.S. followed a different path shaped by historical circumstances. During World War II, wage controls prompted employers to offer health insurance as a tax-free benefit to attract workers.

Medicare and Medicaid, followed decades later by Affordable Care Act exchanges, were added over time to cover those who couldn't get insurance through their job, creating a highly decentralized and convoluted system. In addition to expanding insurance coverage through the exchanges, the ACA -- also known as Obamacare -- attempted to fix many issues with insurers by, for example, forcing them to cover people with pre-existing health conditions and requiring that they spend 80% to 85% of what they collect on medical services.

But the pressure to increase their earnings means insurers have looked for ways to overbill the government and skimp on patient care, always staying a step ahead of regulators. In recent years, they have become vertically integrated conglomerates, controlling doctors, pharmacies and payment-processing systems. This dynamic creates opportunities for self-dealing, putting the onus on the government to act continually to rein in improper practices.