I run a few of my workloads on VMs in Azure. Some of them deal with data and content that changes over time, and accordingly I like to have the data backed up periodically. Microsoft provides the AzCopy tool for uploading files to Azure blob storage alright, and it works very well with managed identities assigned to VMs (and other services in Azure).
But some of the same properties that apply to data also apply to the backups of that data: their value diminishes over time, so keeping backups for an extended amount of time is pointless. Accordingly, I always want to delete old backups after some time.