we have all of these huge applications that are gathering all this data uh and it's out there and theoretically is our data sort of but in reality they control it and you can't actually link the data to each other you only link to accessing the data through their application

My UIs are data/store driven. The UI is just a way to visualize the data. Your data could flow through all of of the extensions and the extensions can make decisions (e.g. setting visible to false). Like middlewares in a Connect/Express/Polka app. And the UI doesn't even know about all this, it just updates with the current state and makes sure it's consistent.