The insurance is only a thing because the tax code allows it as a way for employers to pay people with untaxable money in the form of insurance, so it is not a real insurance market.
Calling it insurance rather than a payment plan or something.
Further it’s got some serious conflict of interest going on with how the benefits are structured. So a plan may cover 1 300$ par of glasses, but not 2 pairs of 150$ glasses specifically to minimize the risk of a race to the bottom etc.