Private health insurance is a shell game. The companies want to cover healthy people only, because that's how they make money. Paying for surgeries or chronic care is not profitable, so they look for ways to avoid doing so. I'd probably do the same in their shoes. So would you.
That's the system we're currently stuck with, and it never made any sense.
There is no logical reason to split the risk pool this way, with thousands of different "insurance plans" pitched to tens of thousands of companies and millions of individual workers. All this does is create confusion and aggravation for consumers and providers, who might be "in network" when you choose them in December but thrown out of network when you visit them in May. It's absurd madness. It serves no one well except a dwindling few insurance executives and some investors.
The way to do insurance is to have the largest pool possible, with automatic coverage and no way to opt out, so that the young and healthy pay even though they don't "need" health care, and that creates enough premium income to cover the old, sick peoples' medical expenses. Basically all civilized countries do this, or something very much like it.
In the USA it's called "socialism" and "communism" and it's been a political non-starter for my entire life. It's one of the three or four key reasons America is not as good as it could and should be.
Here's hoping it will change for the better, and soon.