Yes-- there is no oligarchy in China and North Korea. Oligarchs on China are kept on a tight leash and will be killed for a getting out of line.

North Korea probably has no oligarchs as such

Compare to South Korea, which has a famously corrupt governance at all levels, with policies directly influenced by the chaebols (family-owned conglomerates, whose assets were originally awarded by the US for their willing collaboration with Japanese colonizers)