Report First data model design
This idea comes from the Power BI Unconference from Microsoft Ignite 2019.
Add in the capability for Power BI Desktop to create a "visual first" report design. The idea here is to work in a similar fashion to the way the Datazen built reports. A user could design the reports and visuals, and a data model could be generated behind the scenes with sample data.
After creation of a sample report, Power Query could be used to populate the data model.