How do I find what the Other Storage is being used by? A similar question was asked here, and closed as a duplicate, but none of the referenced questions answered the actual question posed, I'm asking it again.
How to free up &quot;Other&quot; in Storage Management
I have a similar situation with a Macbook Air 2013 running Cataline 10.15.5. Having read and applied the suggestions in those referenced questions, I'm left with the same issue here.

Note the 33gb of &quot;Other&quot; in the last line. It appears that the &quot;Other&quot; doesn't appear in the file-browser under documents.
Effectively, a quarter of my disk is &quot;dark matter&quot; which I can't identify, and thus either use or remove.
I've run First Aid on the disk in recovery mode, and that didn't find any issues.
You can try Daisydisk, Grand Perspective or Disk Inventory X which are graphical Disk space mappers. One of these may have what app the 33 GB is mapped to.
There is also a nice explanation about the &quot;Other&quot; storage and how to free up that space. This is explained in this iMore link here.. Some of this disk space is related to the new Optimize storage feature. Not really new but since Sierra operating system. When Apple added its storage management feature to macOS Sierra and newer, called Optimize Storage, it reorganized what &quot;other&quot; storage is and where it's located on the Mac. Much of it has been divided out through other categories so it's easier to find and remove.