Furthermore history does show communism didn't work. Communism resulted in the deaths and torture of millions of people.
This is also extremely stupid
The US killed how many Koreans? How many Vietnamese? How many Iraqis? Why doesn't this imperialist behavior by the most powerful capitalist country on earth prove capitalism doesn't work? How many people are in prison right now in the United States? Over 2,000,000? How many people are in poverty right now, in the richest nation on earth? 50,000,000? Doesn't this show capitalism doesn't work? Actually, the fact that this is literally capitalism "working" says it all.
Meanwhile the bad stuff you reference about communism resulted from excesses and errors in certain points of history (and even where real atrocities did happen the numbers are always greatly exaggerated). Cuba is more peaceful than the US and does more for its people than the US, even with all its wealth, even considers doing for its own. So why does communism not work and why is capitalism a better alternative?