It would give a lot of insights and enable reports to be C-suite ready if we could add comparison columns to custom reports.
Example: Pivot table with Pipeline, Close date by quater, Amount by quarter and a comparison column with the ability to say show % difference between Q1 and Q4 or Q1 & Q2.
I understand some of these capabilities are in datasets but that is often more advanced than most users can use and not easily available on a dashboard.