Insurance isn't mandatory here. We have medicare, which is tax funded. They have undercut medicare funding though, and introduced a 2-tier system.
So it's increasingly attractive to get private insurance which will cover "the gap" between public health care and your chosen health provider's fee.
Wait, you don't have to have insurance to drive a car?
You most likely pay way more into car insurance than you'll ever have to pay out.
There are some horrible drivers that make up that gap.
It's the same with health insurance.
Smokers pay ridiculous taxes on cigarettes to fund medical aid for lung/heart disease sufferers who aren't all smokers.
This again covers 'the gap'.