Interesting take, so we should allow people to ride without helmets and then when they're bleeding out on the street we should just leave them there if they can't pay.

Yes, we should allow people to ride without helmets.

No, I'm not saying we should just leave them there to die.

But if they can't pay, society will have to. Granted, I guess this isn't technically paying for everyone else's healthcare.

You can contribute voluntarily to charities to help people pay medical debt, to charities that provide free medical assistance or there could be free/less expensive medical treatment given by universities as training to medical students

A priori, you don't know if someone won't be able to pay for treatment, so there's no reason someone should be left to die

The important part is that things should be voluntary and not forced

And if charities/universities are unwilling or unable to give all of the emergency medicine needed?

The same thing that happens when hospitals are unable to give care today in any country

In same vain we could ban ice hockey then :)

Even in the US you would be paying for the risktaking of others because their premiums depend on whether everyone in their insurance pool wears a seatbelt or not.

I don't know if this is legal now in the US, but insurance should be allowed to charge more for people with higher risk-taking, either because of past offenses, or other behaviors