Giving employer benefits tax exemptions is unfair, not supported by law, and is a total disaster.
What it means is you can't quit your job because your employer owns you through your heath care.
If you quit, you lose all the health insurance premiums you have paid in.
Poor people who do not have jobs that pay employer benefits then end up effectively subsidizing the health care of the wealthy who get tax exempt employer benefits.
And by prepaying your health care through private insurance premiums, you lose all ability to influence any quality or cost issues by your providers or insurance company.
If there was some sort of single payer, like Medicare for all, the we would all be paying less than half what we are now for health care, because if nothing else, the providers would not have to spend billions one specialized insurance forms administrators.