I believe that every argument should begin with commonly understood definitions. Capitalism is a social system based on the explicit recognition of private property and voluntary contracts. Communism is the abolition of private property altogether. And socialism is institutionalized aggression against private property and contracts between consenting adults.

Every short-coming of capitalism applies many times over to socialism since the latter does not legally recognize people's right to voluntarily defund or disassociate with unproductive actors in society.

Under capitalism, no one can take a penny out of your pocket or get a second of your time unless you voluntarily give it to them. But under socialism, the state (or council or committee) has the monopolistic privilege to coercively fund certain activities via taxation, which means the right to threaten people with prison if they don't chip in. What makes capitalism unique is the right to engage in the original appropriation (using unclaimed scarce resources) and contracting with others (employees and employers).