How often do health insurers say no to patients? (2023)

So far this year I'm seeing basically "We got $100 off! $0 paid by plan. You owe $xxx" I barely use it, but so far insurance isn't covering anything except basic $x refills

You are on a high deductible plan. With those plans you pay the first $X and after that a percentage of costs (coinsurance) up to $Y.

Sometimes certain things are covered before you hit your deductible other times not.

Yes, but you'll often find that in a high-deductible plan the insurance company gets a "discount" of your $1k med down to $200, which they brag about in your EOB… but the medication's cash price for uninsured people would be $20.

You're out of pocket $180 more than you should be, and paying the $20 cash price out of pocket means your deductible doesn't budge.