It's $75,000 you don't need to pull from IRA, taxed as income, to pay for SS.
The reduction in SS for not working the last years will drop the amount of SS awarded by around $100 a month. The $75,000 saved in the IRA because it's not subject to SS tax offsets that reduction.
When I was calculating how much money I needed to retire, there were several expenses I needed to consider that were no longer going to be owed. SS was one of them and at 6.2%, was substantial. I need much less income in retirement to have the same net to my spending. Meaning I get to keep what I would have had to pay into SS if I had continued to work.
I might want to add that my working income was above the SS max, all of it going to my retirement accounts; IRA, 401K, 457. So I didn't pay SS on those dollars when I earned them and don't now that I draw from those accounts now that I'm retired.
SS withholding is before 401k/IRA deductions...