Most of the platforms you listed are “banned” largely a result of regulatory and data-governance issues. China requires internet services operating in the mainland market to comply with domestic regulations covering data protection, content management, and licensing, which generally includes managing Chinese user data within the Chinese regulatory framework and cooperating with local oversight. Many large foreign platforms chose not to operate under those requirements, so their services were never integrated into the mainland internet environment.

As for Reuters they aren’t banned per say they simply haven’t obtained the licences required to operate in the mainland (to my knowledge).