Government social insurance creates some of the most serious problems in western style democracies. At best, these government insurance programs place tremendous strain on the economy and reduce work incentives. At worst, they may result in the bankrupting of the society. In the United States, Social Security pensions and Medicare are the worst culprits.
There are, moreover, alternative arrangements that would avoid these problems. Some people may favor a fully voluntary system. Others may favor more government involvement, such as a compulsory private system in which individuals are required to save certain amounts for their retirement or are required to purchase health insurance on some kind. (For a discussion in the context of unemployment insurance, see here. For a book comparing private and government insurance more generally, see here.)
While there are arguments for each of these systems, the important point is that they would not involve redistributions. In particular, they would not require the massive redistributions that these existing systems make from one generation to another – redistributions that are unfair, inefficient, and cause serious political problems.