There are several possible reasons for this:
Market competition: In China, the Kindle faces competition from other e-reader brands and mobile devices. There are many other local brands and tablets on the Chinese market, as well as other international brands offering similar products. This fierce competition may lead to a decrease in Kindle's market share in China.
Copyright issues: There are some challenges in digital copyright protection and copyright management in China, which may affect the availability and content selection of Kindle e-books in the Chinese market. Amazon may have faced difficulties related to copyright issues and content licensing.
Retail environment: Amazon’s retail business in China faces some challenges. Amazon China transferred its business to local companies in 2019 and has since focused mainly on cross-border e-commerce. This change may have a certain impact on Kindle sales and promotion in the Chinese market.
It should be noted that business decisions involve multiple factors, and I cannot provide specific reasons for Amazon’s decision to withdraw from the Chinese market. The most accurate information should come from Amazon or related reports. If you are interested in this issue, it is recommended to consult Amazon's official statement or contact its customer support for more detailed and up-to-date information.