The Soviet Communists, the Romanian Communists, the East German Communists, the Chinese Communists, the Vietnamese Communists, the Cuban Communists, the Korean Communists, you name a group of Communists and you get an authoritarian dictatorship, demolition of the economy by imposed wealth confiscation and Socialism, political repression (usually because after just a few years of Communism people would vote it out for a Democratic Capitalist system), etc.
Marx might not have expressed this being the case but it is 100% of the time the case when Communists get in charge.
Aside from that, Marx and Engels were wrong in almost all of their predictions about society and economics.