Ah, there are many many sick people who do not have the resources to pay for care today, even that which will restore them to essentially the level of function they had before becoming ill.
I agree. There are many people in the U.S. who have no medical insurance, and as a result don't get treatment.
How is that different than a health insurance program that pays for care that is not likely to be fruitless and not other care?
If I understand your question, the U.S. health care situation today is different in that the selection of which patients get care and which do not is made on the basis of whether they have insurance, not on the basis of whether the care is likely to be fruitful. I think this could and should be improved. In both the current system and what I think you are suggesting, some people are allowed to go without treatment for strictly financial reasons. Either way we are making money more important than peoples' lives, which IMO means our priorities are wrong.
Would I be correct to conclude that to you, "fruitful care" means care which is likely to return the person to their original level of function? In that case, what of people who have incurable conditions such as brain or spinal injury or genetic illnesses? There is no treatment that will restore them to their original level of function. Should they receive care, or not? What about people with birth defects, whose original level of function is subnormal in some way? Should they be treated?
IMHO individuals should have the option of purchasing a private policy that insures against the risk of being denied payment because a treatment is not likely to be fruitful. A program that is all things to all people will be affordable for only a few.
It sounds like to me like you are advocating a system under which people would pay for insurance (whether via premiums or a paying into a public pool via taxes), but if they suffer a catastrophic injury or illness from which full recovery is unlikely even with treatment, they would not be eligible for coverage, unless they also had a fail-safe private policy. It hardly seems fair to cut off treatment to someone who has been contributing to the system all along, just when they need it most and due to injury or illness are least able to pay out of pocket. But perhaps I misunderstand you?
I think a system which paid for the devastating injuries and illnesses, while leaving the smaller, preventive expenses to be paid for on an individual basis, would be preferable.
I think your suggestion of supplemental policies, which an individual would have the option of buying to increase their coverage, would be a good addition to just about any universal system.