As I assume you know (but some others don't), file systems like ZFS protect you from "bit rot" with checksums for data. Scrubbing is the process of scanning file system data looking for (and correcting) bit rot.
APFS does not checksum data and so does not have a scrubbing process. APFS does not protect against bit rot. I suggest that this is the main criticism levelled at the functionality of APFS.