If insurance companies were free to develop their own policy products I'm quite certain one of them would have thought to offer parents to include their adult children on their policies with an additional premium cost. After all, the young adults are the ones who use health care the least so you're levelling out the risk pool.
Employment provided at least a crude screen. If you aren’t falling over so bad you can’t even work, then you’re a more quantifiable cost.
I misspoke by saying “Make”. There should be no mandate to purchase insurance. Perhaps “make it more financially wise” for people to purchase their own insurance.