On the one hand I am the target audience for this: someone who wants to focus on data and have the frontend "solved" for me.
On the other hand, I have been burned by every similar framework I've tried (e.g. Dash by plotly, many others) when I *need* to tweak one small thing in the frontend, and simply can't because of the way the framework functions. In which case, I have had to rewrite the feature from scratch. So I have found these tools okay for internal tools or proof-of-concept stage, but inadequate for real applications with real users where you need to quickly iterate on feedback in directions you cannot predict in advance.