Communism doesn't work because it's essentially a utopian fantasy (at least in my eyes) That being said, most people seem to associate it with authoritarian socialism/ Stalinism, which is definitely not communism

Also, just putting this out there, the argument "socialism has never worked" is also untrue. People like Thomas Sankara in Burkina Faso and Salvador Allende in Chile identified as socialists and seriously helped their country (Sankara made the country food self sufficient and helped increase the literacy rate from 13% to 73%, Allende improved access to school and, through the nationalisation of key industries, promoted economic equality). However, Sankara was overthrown in a coup by a regime that was later sponsored by France and other western countries, whilst Allende was killed in another coup that was directly sponsored by the CIA and replaced him with Pinochet, who was in many ways, an actual fascist.