Regarding "why Vizro": As we all know it is hard to compare tools like for like, but we see Vizro as a great combination of benefits offered by existing tools (given that some have been mentioned on this thread); it leverages a simplicity and low-code solution approach, but it still enables users the flexibility to customize advanced solutions. It keeps configurations simple even if you create more sophisticated actions/callbacks. It comes with an out-of-the box sophisticated look and feel.
The approach of using a configuration layer to enforce standardisation in the way that components and code is assembled utilises a grammar which is largely tech agnostic, and while it is currently optimised to leverage Plotly and Dash, it could theoretically utilise components from other packages such as StreamLit in future
It's effectively a static site generator aimed at building automated reports and analysis.
https://github.com/evidence-dev/evidence
Previous discussions on HN:
https://news.ycombinator.com/item?id=28304781 - 91 comments
https://news.ycombinator.com/item?id=35645464 - 97 comments