"There are already many legal ways around it and much inheritance income grew tax free."
The only significant money that grows tax free are in retirement accounts besides stock appreciation, which are hardly much for someone with a high net worth. The only issue is with appreciated stock which has the basis of the FMV at death. It would not be hard to change that rule so that capital gains cannot be avoided (of course capital gains ignores inflation as is).
There being ways around it is precisely one of its main problems. Much money is simply diverted to estate planners who come up with the next creative way to avoid estate taxes. Then new tax rules come on, wasting everyone's time for a pretty low revenue producing tax. Inherently, it requires restrictive controls on how people dispose of their property during both life and death. Wealth can be used for power during life (see all the rich men and women running for Congress), can be wasted on extravagance, and it can be given to someone's family. I am not really sure why the latter should be penalized more than the first two.
Outside of my anecdote, I doubt I will ever even be indirectly affected by the estate tax, and when I am struggling and working hard I can resent the trust fund babies, but I am not sure our tax system should be built around envy and spite.