This isn’t about estate tax. Your heirs don’t take anything away from you, neither does the government with estate tax. At the time they take whatever they’re taking, you are dead. Dead people have no use for property.

Besides that, if you don’t want your heirs to have your estate, you can create a will while you’re alive and leave all your property to charity, your cat, whatever. In any event, whatever happens to your wealth it won’t really matter to you, since you’ll be dead.

Edit: seems I misread this. Anyway, nobody “expropriated“ your labor, you sold it at an agreed upon price. If you aren’t happy with the price you got, demand more or make your labor more valuable.