From The Case For Using Subsidies For Retirement Plans To Fix Social Security by Andrew Biggs and Alicia Munnell:
The U.S. Treasury estimates that the tax preference for employer-sponsored retirement plans and IRAs reduced federal income taxes by about $185-$189 billion in 2020, equal to about 0.9 percent of gross domestic product.1 However, the best evidence suggests that the federal tax preferences do little to increase retirement saving. ...
The [report] concludes that it makes little sense to throw more and more taxpayer money at employer plans and IRAs. In fact, the case is strong for eliminating the current tax expenditures on retirement plans, and using the increase in tax revenues to address Social Security’s long-term financing shortfall. ...
This doesn't appeal to me. It's very unlikely to pass. There aren't specific tax revenues involved, just a reduction in tax preferences. I'd be more in favor of dedicating revenues from the estate tax, excise taxes and tariffs to Social Security but I doubt that would be enough to matter much. It's becoming more and more obvious to me that the only solution to the long term funding shortfall is an infusion of general tax revenues. The things that people discuss, raising full retirement age and lifting the cap on wages covered by the FICA tax, even together, aren't nearly enough to solve the long term funding problem.