Are Diploma In Business Analytics actually useful?

Answer 1

Maybe if it comes from a place like Harvard.  Otherwise, you'll be competing against candidates with a degree in the subject.

Answer 2

The diploma itself is just a piece of paper.  The knowledge and skills gained to earn that diploma should be of some use.

What country are you in?  What is the standard level of eduction for a person who would do this job?  What level of education is associated with "diploma" in your mind or country?