This is always a hot topic in Australia. We have such generous healthcare yet people still complain that they have to pay out of pocket for dental work.
While the prospect of having perfect teeth for "free" sounds appealing on paper, everyone seems to ignore the knock-on effects:
dentists will actually become more expensive as they'd no longer have any reason to keep their prices low
the wait times will be increased because more people will be lining up for their free whitening or to fix a lifetime of poor oral hygiene
the quality of care will inevitably decrease as more patients need to be served.
This is the exact same thing we see in hospitals. Nobody goes to the dentist for a mild toothache or because their child is teething. But people willfully clog up the ER thinking they're going to die because of a bad pimple because they know it doesn't cost them anything.
So in the end, the service costs more AND that cost is incurred more often as more people use the service.
Who pays for all that? It comes straight out of your taxes. So you're left paying MORE for an inferior service. It's not just poor economic reasoning, it's a sin of Ozbargain.