The only way to get assets into a scene is to import objects in some file format.
(Blender append only work with libraries).
I think Armory needs a modern way to show assets in game project folders,
and be able to work with drag and drop from folder to 3D scene.
It’s a better and more efficient way to work.
The whole point is to model and create everything in blender. There would be no reason to change that. All the assets should be in .blend files.
The objective was to get global view of assets, why not miniature icons of models or textures previews.
Perhaps this will be possible in 2.8.
While getting assets organized in different Blender files category can be useful.
There are add ons out there that do have previews and deal with asset management but to the best of my knowledge there is nothing planned for blender itself. But then who knows what all they have up there sleeves for 2.8 and beyond.
maybe this would be of help to you https://cloud.blender.org/blog/introducing-private-projects