If you stick with that system that enables and promotes greed, you can then regulate it (rather than make greed illegal and then be surprised that it’s not working). We’d need to actually see socialism somewhere before we can judge which approach is better (both will eventually be consumed by capital), but socialism does have serious persistence issues that need to be considered.
Huh? I don’t exactly have a PhD on this stuff but AFAIK you have to want to get rid of private property before you can claim to be socialist. Social security is just an addon to make capitalism more bearable.