Healthcare in the US is a great example because the government is so thoroughly captured by the industry. There is no reason competition wouldn't be effective for non-emergency care, if it was allowed to operate. You need an MRI, every provider publishes their prices, you pick the one which is the right combination of affordable and a convenient distance from where you live. Naturally the existing regulations make that impossible -- the tax code has major incentives for employer-provided insurance rather than the employer paying you money and you choosing your plan or paying out of pocket, the insurance is given the incentive to inflate rather than control costs because their profit is capped by law at a specific percentage of claims (so more and bigger claims means more profit instead of less), the AMA lobbies to have the government limit the number of medical residency slots and sustain a doctor shortage, etc.
Notice that food is another market where "squeezing customers dry there literally kills people" but it has nothing like the same problems because it has much more competition.