Power BI Desktop is much closer to a Microsoft Office application than an integrated development environment (IDE) tool such as Visual Studio, which offers granular control over the data model. With Analysis Services, business intelligence developers and the teams responsible for Analysis Services models can take advantage of the rich development experience built into SSDT for Visual Studio, as well as familiar management capabilities available in SQL Server Management Studio (SSMS). Additionally, these same tools can be used for both AAS and SSAS models.

For example, the following screenshot from an Analysis Services project in Visual Studio 2017 exposes the DAX Editor window (left) and the Tabular Model Explorer interface (right):

With the Tabular Model Explorer, the model developer has a central location to find, view, and optionally edit the objects of the model. This interface, along with the DAX Editor window, is very helpful when working with large models containing many tables and complex DAX expressions. 

In terms of managing deployed models, SSMS provides a familiar object explorer interface and enhanced support for DAX queries, as shown in the following screenshot:

In the preceding screenshot, the same data model (AdWorksImport) from Visual Studio is accessed from SSMS and an ad hoc DAX query is authored in the query window. In addition to the new .MSDAX files for DAX queries, Tabular Model Scripting Language (TMSL) commands can be scripted and executed in SSMS.