The PRC is almost completely surrounded at sea by other island nations which form a near complete "archipelago landlock" that doesn't exist (as far as I know) a

The PRC is almost completely surrounded at sea by other island nations which form a near complete "archipelago landlock" that doesn't exist (as far as I know) anywhere else in the world. So while it is true that China has lots of coastline, it can't project that coastline out into the Pacific Ocean because it is blocked. News reporting about China's actions often misses this important motivator.