I do financial data analysis and Jupyter Notebooks allows me to run scripts while explaining my findings/arguments about the data within the same space.

It's a convenient way to present both data and narrative to whoever might need to see it.

I also like being able to run snippets when writing scripts, at least when it comes to building/testing. I'm more on the data science side than the dev side though, so that's probably why Jupyter Notebooks appeal to me more than other IDEs.