@Morgenstern72 actually, your own answer was more correct
snapshot is essential for us to obtain CBT data, as well as actual virtual disk blocks placement data on VMFS LUN. This data enables us to backup directly from LUN snapshot.
@Marco, we do not use VMware Tools VSS, so we don't need a VM snapshot for that. We CAN use one, but this is not a default setting, and is not recommended. Remember that we have our own VSS integration.