Also underappreciated, at the end of the day:
{insurance premiums} >= {average cost of care}
If cost of care increases, premiums must increase as well.
There are no healthcare system in the world where the budget is “high enough to be virtually infinite”.
All health systems are all heavily, heavily constrained by budget. The US system is the least constrained (i.e. if you want the latest cancer care paid for, the US is the place with the highest probability it’ll happen), but since there are thousands of insurance plans it’s not even and any two patients may have plans that make different trade offs.
And governments do the very similar math as the insurance companies when it comes to cost-benefit analyses - that’s how they design their benefit offerings.
The difference between systems like Canada (with universal care) and the US is that in Canada the end user doesnt see how the sausage is made.
That’s because the trade offs are the same for everyone and doctors know a given trade off has been made and the technology that is not paid for is just not even brought up to the patient.
Healthcare budget is not infinite but in most countries, it’s high enough per operation that, for a given individual, it’s virtually infinite.
Insurance companies don’t care about the benefit, they just want the cost to be low, it’s not the same thing.