From the recent Duplicacy Backup Failure thread, one can see that Duplicacy documentation should make clearer which purpose the software has (basically incremental backups of user folders, not cloning a whole hard drive incl. the OS). Arq, which I evaluated, too, but ditched in favor of Duplicacy, does this, and furthermore it has a preconfigured set of excludes for the most frequent use case of backing up the user folder.
For Mac OS these are certain subfolders in the ~/Library folder:
~/Library/Saved Application State
Other OSes have other directories/folders which shouldn’t be included, as /dev and /proc for Linux, but I leave that for others to recommend.