Currently the File -> Build schema... option on the menu of the Report Designer program looks and feels very much like the Generic Inquiry (SM208000) screen, except that the Generic Inquiry (SM208000) screen actually has better functionality.
Also, many times it is simpler to fulfill a reporting request by quickly and simply creating a Generic Inquiry screen. Then you can create a report later if the need arises. Currently, you have to manually re-create the Generic Inquiry logic in the File -> Build schema... option on the menu of the Report Designer program.
Also, Generic Inquiries can be exposed via OData which allows them to form the foundation of other reports. It would be nice if they could form the foundation of Report Designer reports as well.
It would be nice if Report Designer could use a Generic Inquiry as the data source rather than having to use the File -> Build schema... option on the menu.