So, you can just distribute your wealth to your offspring shortly before your death.
And they would pay income tax on it, just as they do if you were to give your wealth to them before you die today. That is fine. Having property rights when you are alive is fine. Having rights to a dead person's property with tax avoidance is not.
In the U.S., the gifter has to pay federal gift tax. If you transfer a million dollar property, it will be taxed at 40%. Federal inheritance tax has an exemption up to $14 million.