Wishing someone the "best of luck" or "all the best" is a practice often employed by the middle class as a polite alternative to the colloquial "fuck off". In all recorded instances of its usage, no one who has ever uttered this expression has actually "wished" anything positive on its recipient. In almost all cases, the utterer secretly "wishes" that the recipient would not only disappear, but stop existing as a whole.
"Unfortunately due to the high volume of applicants we are unable to offer you a position. We wish you the best of luck with your future endeavors and will keep your resume on file for future reference."
"I'm grateful 4 the many blessings we've shared and I wish her the very best!"