Imagine, now, a much simpler system in which the government just pays your major medical expenses. In this hypothetical system you wouldn’t have to shop for insurance, nor would you have to provide lots of personal details. The government would be your insurer, and you’d be covered automatically by virtue of being an American.
Of course, we don’t have to imagine such a system, because it already exists. It’s called Medicare, it covers all Americans 65 and older, and it’s enormously popular. So why didn’t we just extend that system to cover everyone?