Edward A. Zelinsky (Cardozo), The Case for Limiting the Estate and Gift Tax Charitable Deductions, 173 Tax Notes Fed. 667 (Nov. 1, 2021):

In this article, Zelinsky argues that all large estates should support the federal treasury and that Congress should limit the estate and gift tax charitable deductions to ensure that they pay some tax.

Conclusion
A balance of competing considerations underpins the durable limits of the income tax charitable deduction. Those considerations suggest that the estate and gift taxes’ charitable deductions should also be restricted. All large estates should provide some support to the federal treasury. As the process of reforming the federal estate tax proceeds, Congress should amend the code to limit the estate and gift tax charitable deductions and thereby ensure that all sizable estates pay some tax.