Why tertiary production is so important to Hong Kong economi

Tertiary production is important to Hong Kong economy because it is the only way for Hong Kong to survive.
Hong Kong lacks of natural resources and land. It is not suitable for primary production. Though there are some fishery, farming and mining activities in Hong Kong, the production cannot support the living of the population.
For secondary production, Hong Kong once the most important production center in the world. However, due to the increase in labor costs, education level of people, competition from other cheaper costs countries, Hong Kong can no longer compete in secondary production.
Eventually, Hong Kong's economy is supported by providing services to China's manufacturers and also financial. Tertiary production is suitable for Hong Kong because it requires less land and natural resources but educated manpower.
Nowadays, tertiary production comprises the majority of the economy production in Hong Kong.