People usually want to know if there’s any benefit to having a personal blog as well as a niche-focused blog (as usually, but not all the time, personal blogs are harder to monetise). I think having a personal blog is incredibly useful, and I always recommend it to everyone, whether they want to monetise or not. I also think everyone should have a personal blog at some point.
Having a personal blog does wonders for your writing and your enthusiasm, and can be the best way to explore, experiment and learn about blogging and how you want to be seen online. Having a personal blog will help you get to that juxtaposition of personal and audience satisfaction much faster than if you were blogging with a restricted niche or business.