Pretend for a moment that everyone receives their annual physical, as medical guidelines recommend. (They don't, but it makes our example simpler.) And let's say that the fair-market price of providing the physical, accounting for all costs borne by the provider and their practice, is $100. (That is an arbitrary number I have chosen, also to make our lives easier). What will be the co-pay for the annual physical for an insured patient?
The answer is that it will be $100 - there is absolutely no risk involved in this situation, so the expected payouts of the insurance company will be $100, and therefore they will incorporate that into their price. (The consumer will actually pay a bit more than $100 in total, because the insurance company has overhead costs, which are ultimately paid by the consumers as well). But of course, that's not the case, because the expectation is that health insurance will reduce these costs, and that people who can't necessarily afford $100 will still be able to have their physical. That's why health insurance isn't really insurance, except in name - we talk about it as insurance, but in reality, it's a wealth redistribution program tacked onto a risk smoothing product.
By definition, insurance is literally not intended to save the insured person money, in expectation. The expected value of all claims will always be less than the expected value of all money paid to the insurer by the insured entity. (This does not hold for every individual, but it does hold in the aggregate - that's where the risk smoothing comes in). The insured person pays the insurer a premium[0] in order to reduce the uncertainty in how much they would have to pay on any given month without insurance.
[0] Not as in "monthly premium", but as in "a premium on top of the expected value"