There are all kind of reasons to reconcile number of files against offline reference source, expected uploaded files, as an indicator for taking action, as a confirmation that files have actually uploaded, especially when using file requests, which do omit duplicates and show received numbers, but not actual files put into a folder.
Replicating or linking Dropbox as a folder on a PC is not an option, when
a) Dropbox exceeds the available space on a hard drive
b) One has more than two Dropbox accounts
c) has two Dropbox accounts but cannot link the two together