3D scanning only gets you a mesh, it doesn't get you interactivity or functionality. If you just want to manhandle a bunch of meshes, modding H3 VR is easy, and there's a 3D modelling program for SteamVR that opens and edits meshes just fine.

Hell, you can even interactively edit things in the Unreal IDE. But it's still a serious task.

Sure, but it's a very useful first step. When you want to do something like, say, 3D printing a case for your bluetooth earbuds, there is no approach that isn't tedious.