It was added in 2010 (#554170) as a split off from a previous cron job. I haven't seen an arguement for why it's useful to keep. Depending on when a mistake occurs in one of the files it backups it will provide variable recovery time of 0 to 24hours.
A testsuite is also available. Instruction on how to run this testsuite are available in tests/README -- Balint Reczey <rbalint@ubuntu.com>, Sat, 12 Aug 2017 18:46:44 -0400