Why is the Dewey decimal system only for small libraries?

The Dewey Decimal System is primarily designed for organizing collections in smaller libraries due to its straightforward, hierarchical structure, which is easy to implement and maintain. However, as libraries grow larger and their collections become more specialized, the limitations of the system in accommodating diverse materials and subjects can become evident. Larger libraries often require more complex classification systems, like the Library of Congress Classification, to better organize extensive and varied collections. Thus, while Dewey works well for small libraries, it may not fully serve the needs of larger institutions.