Hello Steven,
I don't think there's anything available out of the box that you could use to build this. OutSystems does resort to the FusionCharts library, and you could check out the generic Chart webblock here:
But I don't think it can be used to build something as rich as your example - this is a preview available in the documentation:

Looking at the available Forge components, I assume you ruled them out because of similar reasons. The example you shared is visually complex and would be hard to build from scratch in Javascript.
I did some research and I can't find anything that does exactly what you're looking for. The closest I could find was this JSCharting example, but it's commercial software - these sorts of tools take a considerable effort to build and maintain.