The expenses for "common" chronic conditions can be MASSIVE. A condition like rheumatoid arthritis can EASILY exceed $30,000/year in medications alone. Add in frequent doctor visits and related medical issues and that runs up even higher. Without some form of insurance (private or socialized), we would be condemning these people to a life of pain and misery (at best) or death.
A vial of my humalog approaches $300. A visit to the endo is $500 on the bill.
But there is no reason why these things are so expensive! Other than that I have to have insurance so I have to be "in network" and oh, my insurance helpfully consults with a pharmacy benefits manager to decide which medications are "covered."
At no point do I have any choice in any of this. I'm not talking about choosing to have diabetes or not, I'm talking about choosing treatments for my diabetes. Always, it is a conglomerate like UHC choosing which things I have to buy this month. How convenient for them that they choose how much it costs!
There is another major class of things you want to insure against, and it's the big one.
Chronic conditions. You get diagnosed with diabetes. It's costly and it happens rarely in an unpredictable way. You don't know if you're going to get diabetes, or cancer, or something else, so you insure against it instead of being bankrupted by the long-term treatment.
And then the insurance covers your annual checkup for free because they want to catch things early before they progress.