I like this idea, but if one of the main goals is data privacy / security, then hosting everyone’s data in a ‘trusted-third-party’ app seems like the weak link.
What about a solution that focused on easing the distribution of analytic modules to individual users who each host their own data on their own servers (Amazon, Google, private cloud). With a standardized data format, plugins could be written by the developer community to do custom data slicing / analytics / visualization, and then distributed on node/npm or pypi.
An incredibly superficial example of this is the React life by weeks timeline component i created for the Flow dashboard. It sits as a separate npm module and can be installed by anyone, and then plugged into any React-based UI. All it requires is access to JSON data in the expected format.
Such components, with the right API standards, could make requests to any server, perform processing, and display results. Installing modules or components still requires a little bit of technical knowledge, but with an interface layer on top of this process, it could be made to be “drag and drop” for the non-technical as well.