Why is system data taking up so much space on my MacBook Air?

Taken from the MacOS user guide:

• System Data: Contains files that don’t fall into the categories listed here. This category primarily includes files and data used by the system, such as log files, caches, VM files and other runtime system resources. Also included are temporary files, fonts, app support files and plug-ins. You can’t manage the contents of this category. The contents are managed by macOS, and the category varies in size depending on the current state of your Mac. You can manage your data that falls outside the other categories using the Finder or the third-party apps that created it.

My own system data right now is at around 35GB, after clearing up some data from other applications in other categories. However, I've also seen it as high as 100GB sometimes. From my own experience it seems somewhat proportional to the amount of storage I am using in other data categories anyways, which would make sense if "system data" consists of temporary files and caches that are linked to other applications.

Right now I have 57.92GB of free space available on my Mac, out of 245.11GB.