It would be nice if it were that simple, but it's not: https://medium.com/@matthewkeys/a-brief-history-of-facebooks-ever-changing-privacy-settings-8167dadd3bd0
You also have to worry about Facebook's own poor security practices:
https://slate.com/technology/2018/06/facebook-changed-14-million-peoples-privacy-settings-to-public-without-warning-due-to-a-bug.html