The assessment helps track your growth, and secure your promotion as you progress. With a clear visualisation of your skills on the skill score, your supervisor can easily see your development and reward you accordingly, or suggest potential growth areas.
For example, they may see that you excel in UX writing and wish for you to develop yourself in the field of information architecture. The SkillMap is helpful in that it shows direct relationships between skills that you already possess and those you may jump to easily. It can be used to align your development plan with your supervisor.