You have a system in which health insurance is tied to your job because of tax breaks created by Congress i.e. state intervention! It's not a normal or natural way for private health care to evolve. I have private health care and my policy is my own, not connected to my job, for example, and that's pretty typical outside the USA.
Your insurance company may sometimes refuse to pay for tests recommended by your doctor because neither you nor your doctor are directly paying for tests so the insurers are the only parties whose job is to push back on over-testing. The USA is famously considered an over-tested and over-medicalized society in general so arguably they could do a lot more of such pushbacks. If you do some research and think that in your case they're overshooting, then you need a different health plan. The fact that you can't get one due to the job tie is indeed a really broken aspect of US healthcare, and the fix is to fix the tax code so there's no benefit to having employers pay the premiums.
Your insurance company may sometimes refuse to pay for tests recommended by your doctor because neither you nor your doctor are directly paying for tests so the insurers are the only parties whose job is to push back on over-testing. The USA is famously considered an over-tested and over-medicalized society in general so arguably they could do a lot more of such pushbacks. If you do some research and think that in your case they're overshooting, then you need a different health plan. The fact that you can't get one due to the job tie is indeed a really broken aspect of US healthcare, and the fix is to fix the tax code so there's no benefit to having employers pay the premiums.