I think what I'd like to have is a way to edit many (smal-ish) files, which may have different types of editors (hierarchies, graphs, tables, timelines).
Have the UI reflect: files > asset > data more clearly than many of the editors do today. There should be a way to work with many files side by side.
Finally, share common editor parts (outliner, details). I have less preference whether those would be fixed side panels or some holistic dockable mess.