Absolutely I understand.

Just thinking outloud here.. Of course the big winner in the Edit Frame is the fact it's pretty much out of the way and for the most part modeless (on when something is selected and different modes when you engage different modifier keys).

My current best thinking is that it may get somewhat confusing in 3D space-- how to combine scaling (1D,2D and 3D), rotation (plus rotation lock increments), and translation (again 1D,2D and 3D) in one set of controls which is intuitive to use in a edit frame type gizmo. Not to mention having to switch between local and global axis modes. And, one of the hassles of the current 2D Edit Frame is it's difficulty in scaling in one direction orthogonally. Too often it just snaps out of the orthogonal mode and into full scale, which doesn't happen with a Gizmo.

I can see how creating a Gizmo could be quite the task, plus how it will automatically 'get in the way' with the current display. Maybe holding down a modifier key will toggle between Edit Frame (orthogonal view, NONE 3d view) and a Gizmo view in all views.

I've also seen a small gizmo mode icon show up outside the bounding box of the selected object. This can toggle between different gizmo configs: rotate, scale, translate. Perhaps an option but yet introduces even more modes.

Still, fwiw, I think once you add groups and instances and hierarchies, the current system will have to change.