Your answer should be specific enough to sound personal but short enough to feel conversational. Usually two or three reasons are enough if each one connects to your own experience.

A strong answer explains why the work fits you, why now, and why consulting rather than another path. You do not need to list every attractive feature of the industry.

Aim for roughly a minute, then let the interviewer ask follow-ups. If you need three minutes to explain it, the core message is probably not sharp enough. If useful, this guide on consulting interview preparation gives more detail.

mine got way better when I cut it to 2 reasons + why now.

tbh if it sounds like a speech, it's probably too long.