'Why a Master's and why now?' works best as a coherent career decision backed by your actual timeline.

A convincing answer links a skill gap or direction you identified to the specific program you chose. Saying you wanted more education is usually too vague on its own.

Someone transitioning from engineering to consulting might explain how a management Master's supplied commercial exposure, while still acknowledging the hands-on experience they now seek.

Use three points: what you had done before, what you needed to learn at that moment, and how the degree helps you pursue the role you're interviewing for now.

For me "why now" is almost harder than "why master's". I went straight from undergrad, so it wasn't a career reset.