I suspect part of the discussion would be the difference between mere copies of files, folders, and entire drive contents, and backups.

Multitudes of copies of folders and files are not (in my opinion) the same thing as structured backups, part of a backup system. Copies and recovery of the copied data may not provide detection or correction of bit rot, file copying bit errors, directory/folder errors, etc.

Cascading 'copies of copies' compounds the risk of propagating bad/damaged data. When file corruption is discovered, finding the least old non-corrupted version could become laborious.

During recovery operations using a copies of copies system, the user alone is responsible for identifying what files are supposed to go where, and actually putting them there. It is even possible to inadvertently copy things in the wrong direction, writing bad data over good. There is no software watching over to provide guidance or gaurdrails.

I do not use Crashplan and have not studied the documentation. I would certainly expect that the archive has not only detection of bit damage but can correct and recover from some level of archive file damage and still restore 100% of the data from the backup.