The notion that private profit in the long run reduce productivity and efficiency while government price control and command allocation increases either reflects a very deep misunderstanding of the power of the market that can perhaps be traced to some remnant of the most flawed parts of Marxism.
What we do see is that Chinese shipbuilding (both commercial and military) has a lot more competition than what we see in the USA.
Eg. In the military realm
Carriers: 1 US shipyard which has a monopoly versus 2 competing yards in China
Destroyers: China and the US both have 2 shipyards. But China has 7 destroyer contracts per year up for grabs, whilst the US only has 3 which have to be divided evenly to sustain the industrial base.
Frigates: China 3 shipyards versus US 2 shipyards. Again US orders have to be divided evenly because they don't have the volumes for orders to be redistributed.
etc etc
So whilst China has the shipbuilding volume to sustain multiple competing shipyards - the US military shipyards don't really face any competition.