As rule I expect that an app that allows time tracking, also has a time analitycs, e.g. how much time was spent on any task / workspace or by some time period (day, week, month, year and total).
As an argument, 1. I used to share a screenshot with spent time on the work by month to my client to accept payment with my spent hours to the project. In addition, superproductivity provides graphes and charts for spent time by time periods (daily, weekly, monthly)
2. To find out how much time an user spends time into different areas of life: work, sleep and chill.