We would, of course, have to subsidize HSA's for the poor, but we'd be subsidizing up to 40% less cost.  HSAs pay the provider at time of service with no claims processing.

Those of us of drive cars spend an average of about $300/mo out of pocket for our gas, oil, car washes, and tires.  If we mandated that our auto insurance cover those routine maintenance costs, every transaction would require a claim to be processed, and our car insurance premiums would go up by $500-600/mo for $300/mo of "benefit."  And that's what we've done with health care.  And when we're spending someone else's money for health care, we don't care what the cost is.  If it's our HSA money we're spending, we have an incentive to shop price, and an incentive to prioritize as to whether or not we really need the service, because if we don't spend the money in our account, it accumulates.  We don't get anything back from "insurance" if we don't have any claims; with an HSA, we do.  It's like an IRA.