Near retirees didn't already pay for their retirement benefits.
They paid for the retirement benefits of the cohort that retired before them.
A good question to ask your kids is whether they would prefer to have a $1 or a penny that would be doubled every day for ten days. That $1 usually looks like a really good deal, but if they had taken the penny doubled every day for ten days, they could have had $10.24.
So the government initiates social security on the promise that no one would ever need to contribute nore than 3% on the first portion of their income. Old folks didn't live very long then and there were a lot more workers than old folks.
So social security initially was indeed 'free money' to the first recipients who had contributed little or nothing to it. And at first the money poured into the U.S. treasury to support the retirees and everybody felt virtuous and righteous that they were showing compassion for the old folks.
At that time people saved for their retirement, invested and grew their savings, and, if they didn't need it all for their own use, it passed on to their heirs. It was their money.
And then the entitlement mentality began setting in.
Workers didn't feel as much need to save for their retirement because they could count on social security.
And because so much of that money wasn't needed yet, the government started 'borrowing' against it and using it for other things on the theory it would be replaced before it was needed. And government became addicted to having that money to spend on things.
And because the social security fund was so awash with cash, it was expanded to cover other things like people on disability who were still way below retirement age and then their families. And though government felt even more virtuous and righteous at doing such good things, the funds wouldn't quite go around so they raised the social security tax again. . . .and again. . . .and again . . .and again. . .
And old folks started living longer and retiring earlier because they had social security and could. And when there was once 50 workers paying for the social security of one retiree we were soon down to 10, then 5, then 3. When the bulk of the baby boomers retire it will be about 2 workers supporting every retiree.
Your own savings and investments are yours. You can continue to save and grow them or spend them or give them away or will them to your heirs.
Your social security money has not earned a dime all the years you have been paying into it because the government doesn't invest and grow it but spends every penny of it and then some as soon as it hits the treasury. It is not yours. The government could take it all away with a simple majority vote of Congress. If you die before you draw any of it, you lose it all. You can't give it away. You can't will it to your heirs. And the government has used it to mask the true deficits and budget deficiencies for many decades now.
Yes social security should be gradually phased out of the federal government and returned to the states and the taxpayer where it should have been all along.