Google Data Studio is a free report builder that allows you to bring together your data sources, create a consolidated executive summary dashboard, and share it.
By default, reports in Data Studio get data from a single data source. To combine data from different sources, you can "blend" multiple data sources into one report.
Data Studio will not replace a good marketing database. Blending data is a bit limited. You can only blend up to 5 data sources. Also, there is only one way to combine the data, and that is with a left outer join.