A few dozen billionaires in the United States, Europe and Japan have assets greater than the 50 poorest countries. And inside each country, including the U.S., the gap between rich and poor widens all the time. Where there is great inequality there is always great repression. People do not accept exploitation and injustice easily. As the income gap grows, so do the police and military forces that protect the status quo.
Many movements exist to try to reform capitalism.
They can win important gains. Workers can improve their conditions if they unite and organize. Progressive laws against racism and sexism and environmental degradation can get passed if there is mass action and resistance. But as long as the capitalist class remains in power, these gains can be reversed, too. Let the movement slacken and all the old crap comes back.