My parents live in Europe. They have national healthcare. When they need to go to the doctor, they make an appointment, go and pay close to nothing. It does take time to schedule an appointment, sometimes weeks, but this assumes it's not urgent.
if it is urgent, then they can go to the emergency room, or go to an urgent care, or go to a private clinic. Even in a private clinic the prices are very low compared with the prices in the US.
The issue with health care in the US is that prices are set with the expectation that the insurance companies will pay. This is why a hip replacement costs $35,000 +. If the health care providers expected the cost to be paid by the consumer, then it would cost as much as a TV. And this is generally what happens in Europe even outside of national health care.