This too! I've seen in happen as well in my quest to delete a couple years ago.
The UX is useless by design to make it really hard to bulk delete, the backend is shitty and you can't see your content on friend's walls that disabled their account.
It is bad to the point that you wonder if it is on purpose. My guess is that it is. "Shitty product" as a deterrent to deletion.
Try building a scalable database to billions of users on ad revenue and make it retrieve all data from years ago within the time constraints that users want to see newsfeed items in, you'll see ;)
The UX is useless by design to make it really hard to bulk delete, the backend is shitty and you can't see your content on friend's walls that disabled their account.
It is bad to the point that you wonder if it is on purpose. My guess is that it is. "Shitty product" as a deterrent to deletion.