Basically they are about (specially Blackshirts and Reds) how “libertarian” socialist experiments all failed, and were ultimately destroyed by national and international bourgeoisie.
I think Critique of the Gotha Program by Marx is much better than the Communist Manifesto, as it’s also a critique of the libertarian socialist Germans.
Like, if you want to get very sad, read about the politicides in Indonesia, Korea, South America etc. Communists (and I include anarchists, libertarians socialists, democratic socialists etc. here) have to organize in strong movements to survive.
All communist experiments that lasted more than 1 years were either MLs or Maoists.
We really should look at this and try to learn from it. It’s a fact, it’s just something that has happened.
We have to understand why democratic socialism is vulnerable to being exterminated, and why ML and Maoism aren’t.