Steve Wamhoff (Institute on Taxation and Economic Policy), The Estate Tax is Irrelevant to More Than 99 Percent of Americans:

The Reach of the Estate Tax Is at a Historic Low
The federal estate tax is one way that Congress decided, over a century ago, to ensure that families passing massive fortunes down through generations contribute to finance the public investments that made those fortunes possible.

Families lucky enough to accumulate enormous wealth are the greatest beneficiaries of the public investments we all finance through taxes. The wealthiest Americans acquired their position because their corporations use public roads to ship goods, their companies employ the workforce created by our public education system, their customers buy products derived from government-funded research, and their investments are possible because of the courts that define property rights and the public safety personnel who enforce those rights.

All Americans benefit from these public investments, but it is beyond doubt that Jeff Bezos, Elon Musk, Michael Bloomberg, and other billionaires have benefited more than others. The federal estate tax is one part of our tax system that provides a mild corrective to this imbalance and to the economic inequality that has rocketed upwards over the past several decades.

And yet today the estate tax is the weakest it has been in its century-plus history. Policy changes enacted under presidents of both parties have cut down the reach of the estate tax, but the current provisions — part of the Tax Cuts and Jobs Act signed into law in 2017 by President Trump — have weakened the tax more than ever.

In 2019, the most recent year for which data are available, only 8 of every 10,000 people who died left an estate large enough to trigger the tax. This is the lowest share of estates affected by the tax shown in all the annual data provided by the IRS (with the exception of 2010, when the estate tax was effectively temporarily repealed).

Other Key Findings:

• The Estate Tax Exemption Has Risen Substantially Over the Past 20 Years
  Legislative changes under presidents of both parties have increased the basic exemption from the estate tax over the past 20 years. This has cut the share of adults leaving behind taxable estates down from more than 2 percent to well under 1 percent.
• Less Than 1 Percent of Adults Would Leave Taxable Estates Under Any Proposal Before Congress
  Historical data on the share of estates taxed each year demonstrate that less than 1 percent of adults would leave behind taxable estates under any proposal before Congress. 
• The Share of Estate Assets Going to the Estate Tax Has Averaged Around 20 Percent in Recent Years
  While the federal estate tax rate is currently 40 percent and has, at times, been higher than 50 percent, the share of estate assets going towards the tax is almost always much lower and has averaged around 20 percent in recent years. 
• Most of the Estate Tax is Paid by the Largest Estates
  Most of the estate tax is paid by estates worth more than $20 million; in recent years the majority has been paid by estates worth more than $50 million.
• The Estate Tax is Sometimes Misunderstood as Double Taxation
  Contrary to one criticism of it, the estate tax does not result in “double taxation,” and, in fact, much of the assets subject to the tax are unrealized capital gains, income that would escape taxation forever if not for the estate tax.
• Congress Should Close Estate and Gift Tax Loopholes
  Several tax provisions, including the federal gift tax and several rules related to trusts, are designed to prevent people from avoiding the federal estate tax, but they are rife with loopholes that further reduce the reach of the tax and which Congress can address legislatively. 
• Congressional Republicans Are Not Done Cutting the Estate Tax
  Even though the Trump tax law has whittled the estate tax down to its weakest level ever, most Congressional Republicans have, once again, signed onto legislation that would go even further, repealing the estate tax altogether and cutting the gift tax. The last official estimate of this perennial proposal, provided by the Congressional Budget Office in 2015, concluded it would reduce revenue by $269 million over a decade. The revenue impact today undoubtedly would be much greater.
  As the figures in this report have demonstrated, the hundreds of billions of dollars forfeited by the federal government under this proposal would go to a fraction of 1 percent of Americans. This would further enrich those families who already have benefitted more than anyone else from the society and economy that all Americans have worked to build and paid for with their tax dollars.