The one thing missing from Capital in the 21st Century, because it would have overshadowed everything else, is the massive transfer of wealth from the rentier class prior to WWII: both from the pogroms of Russia and then the Soviet Union, and the confiscation of wealth and property of Europe. Basically the post-war boom was fueled by money stolen from the Jews. Piketty does point out that Chicago-school monetarism is pretty much bullshit because its models are all based on that massive influx of wealth, which is one of his arguments for bailing on the US. But yeah - think on that for a moment. Saint Milton Friedman and his posse? Yeah, their economics work best when your initial conditions involve six million dead Jews.
Hey - you tell somebody they can shoot their neighbor and take their farm, or not shoot their neighbor and get shot by their other neighbor. Before too long the only people left are the guilty ones. Worked in Cambodia, too. You were either the bourgeoisie or the survivors. This is why the whole "Trump therefore we're one step away from the Third Reich" canard bugs the shit out of me. Ain't nobody wanna steal the resources of those uppity, wealthy black people.
Richard Pipes pointed out that the Bolshevik revolution was pretty much a small cabal of intellectuals channeling the discontent of the proletariat into replacing the monarchy with... a small cabal of intellectuals. And then the proletariat got rid of them, too because fuckin'A it's not like they were royalty or anything.