Although some of this planning is used for smaller estates, more standard planning (gifts within annual gift exclusion or for medical or tuition expenses, use of the lifetime exclusion of spouses, use of the marital deduction, etc.) is used to substantially reduce or eliminate tax liability.
For those of you who already have health insurance, the only thing this does is make your health insurance more secure, because it means insurance companies can't impose lifetime limits or use fine print, so when you really need it, suddenly the insurance isn't there.