A use case from real life.
I setup my 2 tablets 1 phone and PC to do a one way sync. Or so I thought… it turns out “send only” is not as the name suggest. No it creates differences (naturally) as different files are saved and not synced to the other devices. but then a “override changes” button appear. I thought "it will override the error (changes) log or GUI. I did not expect it to remove ALL the files on the other devices (worst, I thought, it would only mess up the device I pushed the button on), I did after all set it up as one-way. So if a developer reads this please change the wording or at even better make en option for true one-way.
And no, I cannot do an undelete as the PC has a SSD with TRIM enabled. Nor does it seem that android has the option for non-rooted devices.