That's not weird; it's essential for the system to work, because you can rapidly move from "never go to the doctor" into "seven figures of healthcare spend" without much warning.
We used to have "high risk pools"; it was horrific. https://www.kff.org/affordable-care-act/issue-brief/high-ris...
Setting aside the reality of the system which will happily collect premiums for 40 years and then use any slightest technicality to avoid paying in the end, ie like changing jobs or providers and it's like you were born on the day of that switch and haven't been paying in your whole life. That is a seperate issue from the simple concept that the young somehow "don't need" to be contributing to the health care pool because they "don't need" to dip from it.
In this, there are no individuals and it's not some elective luxury like how much you want to blow on toys.
Merely in the US, we have been treating it like it was, except even worse, because when I buy a fancy over the top steak, I know the price ahead of time and get no surprises after the fact either. I don't just get hit with $500 steak bills with no warning or choice or recourse and thank god my boss takes $12k out of my salary so that I only have to pay a $50 deductible and fill out 3 forms correctly for that $500 steak I didn't ask for...
You get a high deductible catastrophe plan, and bolt on a Direct Primary Care provider for simple things. The DPC is a doctor who you pay a small retainer (My guy is $70/mo) and the main reason that the cost is so low is that he does not need to staff a billing department due to simply not integrating with insurance at all. I keep $10K in an HSA to cover my deductible if I need to.
DPC doctors also keep a much smaller patient roster so it is pretty easy to book time with him and he isn't being pressured by some middle manager to keep every interaction at 10 minutes or less. Once you see how this all works it's easy to become singlepayer-pilled because wow the whole medical scene could pay providers better, offer higher quality services, and have competitive pricing if we could just get around to deleting the billing department and insurance company.
https://www.investopedia.com/articles/personal-finance/12071...
It would be sensible if we were talking about one society-wide pool (ie single payer), since those younger people would end up being subsidized as they developed health conditions. But as it stands having many pools run by independent companies is fraught with perverse incentives, since an "insurance" company is quite happy to have you as a customer when you're paying in, but much less happy when they're paying out.
If someone gets a chronic condition while covered the company isn’t paying out a lifetime benefit, so they soon need to renegotiate rates while sick even though they had insurance while they got sick.