Memes

That's not really an accurate view of the Soviet Union. Lenin didn't take power away from the soviets, they were still the driving force of decision-making. Thanks to achieving a socialist system, life expectancies doubled, literacy rates tripled, healthcare and education were free and high quality, working hours lowered, vacation days increased, housing and employment were full or nearly full, and they went from feudalism to space in half a century.

Lenin didn't "kill all of the other communists." The vast majority sided with the bolsheviks, and others fought against them and lost in the civil war. It wasn't like Lenin pushed a "kill everyone who disagrees with me" button, there was an active civil war with people killing bolsheviks and the Red Army as well.

The Soviet Union also didn't really fall apart simply due to Khrushchev, Gorbachev, or Yeltsin alone. They contributed by undermining the socialist system and introducing parts of government meant to work against each other, but the soviet union still functioned well until it was illegally dissolved.

All in all, you have a very inaccurate view of Lenin and the Soviet Union, I'd say. It was the single most progressive force in the world throughout its existence, and figures that you list like Castro directly owe at least some of their success to Lenin and the Soviet Union.