Why does file control blocks not suited for DOS 2.0 and above?

File Control Blocks (FCBs) are not well-suited for DOS 2.0 and above primarily because they are limited in functionality and flexibility. DOS 2.0 introduced a more sophisticated file system that supports long file names, directories, and more advanced file management features, which FCBs do not accommodate. Additionally, FCBs require direct manipulation of file data structures, making them less efficient and harder to manage compared to the newer file handling methods introduced in DOS 2.0 and later versions. As a result, the use of FCBs is largely deprecated in favor of the more versatile file handling APIs.