I'm not saying it will work, but in fact it has never even been remotely close to attempted. The two key tenants of keynesian economics is government CUTS spending in the good times and saves and Increases spending in the bad times with your savings in order to balance out the peak and trough of the private sector. We have not once ever done the first half of it so its impossible to tell if it would help smooth out the cycle or not.
Socialism has been tried dozens and dozens of times as has communism so its not even remotely a similar argument.
Socialism/communism and Keynesian Economics both fail for the same reasons.
They enable Control Freaks and ignore human nature.