No one's talking fantasy hypotheticals except for you. The "reality" that you're claiming is not at all actually reality considering that every other industrialized nation on the planet pays less for healthcare and prescription drugs than we do in the United States. If private industry can drive prices down, then so can government. The USPS was the poster child for efficient and effective government service until Republicans decided to absolutely decimate it because of lobbying from private industry. Government services don't need to make a profit, they don't need to lobby, and they don't have any of the greed-driven motivation that private companies do.

You're either being intentionally obtuse or you're intentionally being misleading for some reason. This isn't rocket science. If two things are equal and one has the requirement to also generate profit, there's no way the other can possibly cost more.