Customers may decommission VMs that contain UIM robots running on them. Therefore, they want to permanently remove the robots from IM/USM.
The order in which the steps are followed is important.
The Help doc on 'How to Delete Devices in USM' focuses on discovered devices and does not discuss the complete process for permanently deleting robots.
Customers may follow the Help documentation on 'How to Delete Devices in USM' assuming that it also includes robots.
How to delete robots in UIM when a VM with a robot has been powered off/decommissioned: