Social security schemes and government-guaranteed pensions mean that the government (=the voters) decides how much each currently productive worker has to give away, and how much each retiree gets.
Private retirement funds mean that for each retiree, the amount of money earned from their own former productivity which they relinquished into their retirements fund AND the amount of money they acquired otherwise and put there AND the management of the fund AND other economical factors influencing it decide how much that retiree is allowed to take away from those currently productive.
Finally, the millenia-old "retirement plan=loving children" means that how much each retiree gets depends on how many children they were able to have, how many of those survived, how productive they are, and how much they're willing to give up according to their character, how much they love their parents or how much social pressure towards supporting your parents there is.
The mentality of a mugger.
I usually don't bother responding to this sort of tripe, but it's so easy to prove you wrong that I couldn't resist.
The difference is that, if you really feel that taxes are such an injustice, you are free to leave. Voila, end of problem. Would that I had had that option when I was robbed at gunpoint at couple years ago.
Seriously, put your money where your mouth is and light out for that splendid anarchic paradise you and your ilk dream of so fervently. No one is stopping you and you wouldn't be missed.
What's that? There's no WalMart or fire department in Mogadishu? Bummer...
The difference is that the government's actions are based on laws, which were passed by elected representatives and thus indirectly by the public. Not "forking over" to the government is the same as not paying a debt and claiming that you didn't personally agree to contracts being actually binding.
Maybe you're one of those idiots who actually believe you can have a functioning society without rules that everyone has to adher to even if they personally don't agree with all of them, but that belief does not make it true.