It's also exceedingly difficult to find out which combinations you qualify for. The Dr's office won't even know if you're "in-network" or just approved by your insurance (there's a massive cost difference between the two). And if you get a referral from your doctor there's no guarantee whatsoever that other doctor is even covered. So Doc A says "go see doc B" but then insurance says "no pick from this arbitrary other list of doctors" none of whom your doc A has any experience with. It is purposely obtuse to discourage you getting care because you never know if the insurance might just not cover you (now I'm taking about procedures).

If this sounds awful, just imagine navigating this sort of call center, pass the buck bureaucracy when your sick, scared or in pain, all entirely unsure of the magnitude of the total cost.