Except when you really need an efficient health insurrance system, like cancer level efficiency. At least it's what I learnd from following US politics these last 3 years on reddit.
I mean, I have cancer and my health insurance in the US is about as good as can be expected, which unfortunately means almost nothing because we're terrible at cancer we can't cut out of the body. If I didn't have this healthcare I'd probably be dead already and leaving a mountain of debt for my family. The costs to my insurance company are insane for treatment. I'm easily costing over 100k/mo for basic treatment.