As a Roblox developer, it is currently a long, arduous task to add preexisting assets to the asset manager. For example, the asset manager allows for users to upload images, meshes, packages, audio, and models. The issue lies in the fact that users must upload a file from their device in order to add it to asset manager. When a user is adding images, meshes, or audio, this can make sense; however, models and packages are both created within studio. If a developer wants to add a model or package to the asset manager, they must create in studio, export it, and import it. This makes for a highly inefficient approach. To improve this process and make it more streamlined, it would be beneficial to allow developers to drag assets (or otherwise) into the asset manager directly from studio.
Audio is still an issue, if the api endpoint to add an audio asset to the asset manager fails (such as it did today for 5 of my audios) your quota for audios is still used (since the audio was successfully uploaded) however there is now way to attach these back into your asset manager without fully reuploading them and even if you don’t run into an issue like that, you still need to use up one audio in your quota for every game you wish to add the audio into the asset manager for. In-fact, Roblox would benefit from this feature being in-place since as a developer I would no longer need to upload 40 of the same decal just so I can have the ease of access of the asset manager in all my games. 
That’s a really good point that I didn’t address. If a developer wants to use an asset in the asset manager across multiple games, they should absolutely not have to reupload the asset each time. That creates a tedious process resulting in a very cluttered inventory. Trying to go through your owned items in toolbox after using asset manager in such a way would be extremely hindering to the development process.