From a recent paper by John Sabelhaus and Alice Henriques Volz:
…the present value of Social Security benefits for everyone who has paid anything into the system was $73.3 trillion in 2019. Thus, the present value of Social Security benefits is estimated to be roughly double all other household-sector pension and retirement account assets combined, and approximately three-fourths the size of all conventionally measured household net worth. Social Security is also an important retirement wealth equalizer, as employer-sponsored pension and retirement accounts accrue disproportionately to high wealth families.
…the bottom 50 percent of persons aged 35 to 44 in 2016 had average Bulletin net worth of only $13,500. However, the same group had average expected SSW of nearly $40,000, the difference between a PDV of benefits around $125,000 and a PDV of taxes around $85,000. Again, this is unsurprising given that low wealth individuals have much lower lifetime incomes, and the Social Security tax and benefit formulas are inherently progressive, even though differential mortality offsets some of that redistribution….although incorporating SSW into household wealth has a substantial impact on wealth inequality levels, it does not change overall trends in top wealth shares. While the top ten percent share of SCF Bulletin wealth (within age-sorted and person-weighted) increased from 58 percent to 66 percent between 1995 and 2016, the expanded wealth share that includes both DB wealth and SSW increased from 40 percent to 47 percent.
That is via the excellent David Splinter, one of the most important economists working today, and here is his new paper Presence and Persistence of Poverty in U.S. Tax Data. And here is the previous MR post on wealth inequality and social security.