Why was there a town meeting abroad in ancient times but not in China?

Let's start with China. China has a vast territory and a large population, while ancient Greece is a small country with few people. Secondly, from the perspective of civilization, the coastal areas of ancient Greece are river civilization and marine civilization, while China's vast territory is continental civilization and agricultural civilization. Finally, talk about the system and rulers. Democracy appeared in ancient Greece in 594 BC, and the contradiction between nobles and civilians intensified. Solon became consul and carried out reforms. Democracy began to be established, and the citizens' assembly was established as the highest authority of the country. A 400-member parliament and a citizens' court were established, and a proportional representation system and a lottery election law were adopted. Then Clety further developed democracy, Tao Exile Law and a show of hands. Then Pericles developed democracy into a golden age and finally established democracy. In China, in 22 1 BC, the Qin Dynasty destroyed six countries, unified the whole country, and established an autocratic centralized system, including the Yellow Emperor system, the three public officials and nine ministers system, and the supervision system. Moreover, China is a unified multi-ethnic country. Centralization is mainly manifested in the supremacy of imperial power and suppression of people's thoughts. So, that's basically it.