Why can't health insurance be like car insurance again? Why can't individuals negotiate premiums? Why can't individuals switch to another insurance provider a

Why can't health insurance be like car insurance again? Why can't individuals negotiate premiums? Why can't individuals switch to another insurance provider at any time? Why can't insurance providers cover 100% over anything prescribed by medical practioners? Seriously, why does any medical treatment in America have to be so opaque and stressful? We are regressing as a society if life is not becoming easier.