When you use Analyze in Excel, MDX queries are sent to the Power BI dataset. If you have a PivotTable with 10 measures, the performance is usually slower compared to a similar Matrix in Power BI with the same content. Power BI generates DAX queries. One of the reasons why this difference exists is that the DAX query is optimized using a process called "fusion", which includes in a single storage engine request the aggregations required for multiple measures, whereas this feature has not been implemented for MDX queries. Implementing fusion for MDX queries would dramatically improve the performance of many pivot tables in Excel where there are many measures in the same pivot table.