What good is akonadictl fsck?

[KMail 5.4.3 on Fedora 25, using only POP3 accounts]

If it doesn't fix anything?

I have a crapload of "Item "12345" has no RID" messages that aren't going away 
over numerous fsck/vacuum cycles. I've used akonadiconsole to see that in fact 
Item "12345" does not have a RID, but can't delete it from there either. I 
also have some Collections with no RID.

In KMail this breakage manifests itself with the dreaded infinite zombie 
"Retrieving folder contents" message. Akonadi has been around since 2011 and 
it still can't keep from wetting the bed on even a trivial POP3 mail setup and 
still doesn't provide a better way to correct things than "delete and 
reconfigure." Akonadiconsole gags in its own special ways and offers no help 
even if I want to try to learn the innards of the database and fix things 
manually.

How does this make KMail better with Akonadi getting in the way?