It's fair to those who are too old to really accumulate a good nest egg for retirement. It provides them the security of the current fixed income Social Security program. It's fair to those who can actually accumulate a substantial nest egg. It provides them a real retirement fund rather than IOUs from their neighbors. The truth is the government always misuses money.
Career politicians have a strong desire to control the spending of as much money as possible.
Their honor and prestige depends on the size of the budgets they control, not on whether they did the right things for the people back home who elected them. That's the honest truth. You can honestly control and manage your money better than career government politicians. Your retirement money belongs with you, not with public servants hungry for power. This is the best system.