Provide more control over restores (disk name, NIC name, Availability Sets etc)
When you restore a VM, it creates an automated name which is tens of digits long, and provides no obvious association with the VM. The same goes for the NIc. When environments have been deployed by ARM templates, they usually have a neat and concisely defined naming standard which goes out the window when restored.
Additionally, and crucially for mission critical systems, VMs that are in an Availability Set are not restored back in to their AS when they're restored, which given you (for reasons I just can't understand) can't add a VM to an AS after creation, the backup and restore is essentially rendered useless! The only workaround i've thought of is to sysprep and take and image, then redeploy. But that is NOT an enterprise class solution to support business critical services.