Why is it sent to Wujiang by express delivery to Shanghai?

Transit in Wujiang, the national express transportation is like a Okumo network, and each express company has its own transportation route. It's not point-to-point transportation, just like going from the mainland to Hong Kong usually passes through Guangdong Province, just like the mail to Linzhi, Tibet may arrive in Lhasa first. Mail from A to B may also need to be transported to C, especially by land.