The mainstream browsers allow us to manually delete browsing data “newer than x days/weeks/months”.
This means that the most recent cookies/history/cache are discarded, instead of the oldest data. However, the newest data is typically the most useful and we’d much rather sacrifice the oldest data (who cares about cookies from last year). The mainstream browsers are making it unnecessarily uncomfortable for us to get rid of old browsing data.
Thus, a much more usable functionality would be “delete browsing data older than x days/weeks/months”.
The user should have the option to manually trigger deletion or to have it auto-executed regularly. Besides, the setting should be configurable (e.g., only delete browsing and download history, but keep cookies and site settings … or even set deletion intervals by sub-type).
Ideally, this functionality would exist across all platforms (desktop / mobile).