Ultimately, you need to think through these yourself. It's super important that you answer this question genuinely! Now, in terms of options, the following are the most common:
- Extensive exposure (across all level of organization, across all types of company problems, across industries)
- L&D - mentorship, learning from the best, etc.
- Enjoy solving client problems in diverse teams
- Enjoy strategic thinking and the types of problems you find in strategy
Remember that, for the why strategy consulting question, you need to do the following:
- You need to summarize what you did before along the theme of consulting aspects you liked and consulting aspects that were missing
- You then combine those two - i.e. I know I like + am good at x, y, and z which is required for consulting, and I really am excited to get a, b, and c
- You finish with a "mini" why x company
To your specific question, you need to highlight what you like about your past roles AND these aspects should be things that are valuable to consulting (i.e. problem solving, critical/structured thinking, etc.).
Then, you have to talk about what aspects consulting has that appeal to you (larger scale, bigger impact, client facing, etc.). You need to emphasize that you enjoy this and are good at it (and flag past experiences, internships, etc.)