Socialism does a few things.
1. It supposedly allows a person to obtain self-sanctification, because they are supposedly doing works of good.
2. It mollifies the less motivated, because they are kept from experiencing the full consequence of impoverishment, so they are less likely to be bothered by trying to succeed. Why would I try to obtain skills for a better job when I only have to wait for a higher minimum wage to be enacted?
3. It protects the economic advantages that the rich have by keeping those who might become an economic competitor, because you keep draining them of resources that they could otherwise use to get ahead in life. It acts like an economic tread that is set against stairs and set at a high speed. You only get ahead in a socialist system if you can manage to outrun that treadmill.
As Eric Voegelin had said, totalitarians always wanted to imminentize the eschaton. That said, a lot of them were just in it for the exercise of power in the service of slaughter and atrocity.