> Adding a new file, for example, requires that the filesystem compare the new item name to the name of every other file in the folder to check for conflicts, s

> Adding a new file, for example, requires that the filesystem compare the new item name to the name of every other file in the folder to check for conflicts, so trivial tasks like that will take progressively longer as the file count increases. Not necessarily. Any file system worth its salt is using B-trees or hash tables, where file name existence can be checked in respectively O(log n) or O(1) time.