Why do Facebook profile pictures fail to be fetched?

In the last year Facebook was in the process of deprecating the use of global user IDs, in order to increase users privacy, redefining their privacy policy regarding information sharing between apps.
Recently, this process came to an end, and now FB no longer supports searching users information based on their global ID/username, that includes their Profile pictures.

For example, while Mark Zuckerberg has an active Facebook account:
https://www.facebook.com/zuck

His Facebook account's details (including the profile picture) are unavailable publicly as they used to be:
https://graph.facebook.com/zuck

If you're utilizing your own FB app, you should use the unique, app-dedicated, user ID which was provided to you by Facebook (for every user who signs to it) in order to fetch this user's profile image.

UPDATE - 

For example in NodeJS:

cloudinary.image("65646572251.jpg", {type: "facebook"})