The All users count available under the Users dropdown in the Piano dashboard and the number shown when clicking on Users → All users in the dashboard view sometimes don't match. The cause for this discrepancy is caused by disabled and deleted user records.
For example below, there are 1.2k Users in the dropdown vs. 3,675 in the Users dashboard view.
The Piano API endpoint here returns the count under the Users → All users dropdown.
A full list of active users can be downloaded via this button in the dashboard: