Claiming socialism had “barely any social climb except at the beginning” unlike capitalism is not something that you can do while maintaining any shred of honesty. The reality is objectively the complete opposite. While there are plenty of valid criticisms of the USSR, access to education was not segregated by wealth, top universities were open to all who knew their shit, and throughout its entire history party leaders tended to come from humble backgrounds.

Now, compare the above with the USA.