- Imagine, you're living outside of USA/UK/Europe.
- Formally, it's possible to proceed with "Permanently delete my account".
- You will even receive email assuring you that two weeks later profile would be completely deleted.
- Then, couple years later you'll occasionally seen email from facebook that someone tried to log in into your ("permanently deleted") account.
- You'll try to log in, probably restore and change the password among the way.
- And after that you'll be successfully logged in. And the profile's state would be like nothing changes. Nothing. Completely.
- You'll contact Support. Seriously? They'll ignore you.
- Maybe some interaction with 3rd-party websites triggered cancellation of the process, you thought.
- Then, you'll implement blacklist just to avoid any interaction with facebook, something similar to: https://pastebin.com/FAV2f9eA and try to repeat the flow again.
- Then another 2+ years later situation will repeat again. Deja-vu. And again. And again.
There's no way to delete facebook profile if facebook didn't really care about its users.