The fact that there's a mature product doing what you want to do is a good thing. It means there's a market for what you want that's large enough to sustain development.

You can easily distinguish yourself from Citizen by targeting a different demographic, different branding, different UX, interpreting the data in a different way.

Just look at how many businesses there are in any industry that deliver the same outcome for their customers but in a slightly different way.

What you're describing could be a really good news source giving live on-the-ground information to people.