Which is to say don't propose something until you understand the unintended side effects. You can get your desired result but while making everything worse. (this paragraph applies to everything in politics)
I think the American experiment in trying to provide market health care has demonstrated that you can, in fact, have a 'free' market for healthcare, while making almost everything about that healthcare worse.
Your vision benefits enjoy similar tax breaks, but I've yet to see an optometrist try to bill someone without benefits $800 for a vision exam, or $4,000 for a pair of glasses.
Its not the tax break. It's something else.
Vision doesn't work that way because enough people don't have basic vision care that they won't stand for the complexity.
I'll contend (though of course there is no way to prove this) that if we hadn't had the advantage to company provided insurance the complex billing wouldn't have developed in the first place.
No reason we can't have something similar that in US health care as far as I'm aware, at least for the happy path where the patient is lucid and in a reasonable state of mind up front. But then again, why do we have to worry about this when plenty of countries have a basically-zero-fee system in place?