We have configured Service Requests which need approvals.
As long as this request is waiting for an approval, you have access to the name of the Approver in Smart IT:
Once the approval is done, the Smart IT-User doesn't have any chance to see which user has approved this request. This information is just gone, but might be very helpful (e.g. in case of further enquiries, or to see which of the users of an Approval Group has finally approved the request):
In old ITSM, you still have this information (e.g. in a Work Order click on "View Service Request" and there you will see the Approval History):
From my point of view, this is a missing functionality. Obviously the system is able to show such an Approval List (as you can see when the request is not approved yet). So I don't see any reason why this list is not available once the request is approved.