That scratch directory is %TMP% or %TEMP%, I think, but it definitely always is on the same disk, typically C:

If you unzip files to another disk than where that directory lives, it unzips to its scratch directory, then _copies_ the extracted files to their destination, and finally deletes the scratch files.

That's bad in itself, but doubly so if the disk where it unpacks doesn't have room for the unzipped files.

Mac OS had a system call "Give me the temp directory on this disk" (FindFolder) that made it possible to extract to a temp directory and then move the result to the destination. That call made it into Carbon. I don't think macOS still has it, but it seems UnArchiver does the right thing, anyways.