Employers and customers decide who to employ based upon many things, including:
No single thing will ever ensure success in a job interview, or engagement of your services.
Learning and building all of these things is a life long endevour. People who grow these assets will grow their careers and be successful in good times and bad.
Do not make the mistake of thinking it is as simple as getting a qualification and being set for life. Qualifications can help get the attention of an employer; but they have very little long term impact on your career.
The long term impoact comes from what you learnt when you studied; and how you built on that after studying.