Xuzhou is one of the main tea producing areas in China, so it is not surprising to choose Xuzhou as the origin of tea bags in modern China tea shops. Here are some possible reasons:

1. Geographical advantages: Xuzhou is located in the east of China, with suitable climate and soil conditions, which is very conducive to the growth of tea.

2. Rich tea resources: Xuzhou area is rich in tea planting area and varieties, including green tea, black tea and other kinds of tea. This makes Xuzhou one of the important tea production bases.

3. Historical and cultural traditions: Xuzhou has a long history of tea culture in China, and the skills of planting and making tea have been inherited and developed locally.

At the same time, it should be noted that the actual origin and material source of tea bags in modern China tea shops can be different according to the specific conditions of the products. You can check the product packaging or related information to obtain accurate origin information.