Windows server 2022 thin provisioned drives

Hello there,

I am using Proxmox as a hypervisor and running a Windows Server 2022 mainly as storage on it.
I passed several disks as scsi to the VM and within Windows they are being recognised as “thin provisioned”.

Question: Can someone tell me, why I do need to allocate 64 GB RAM to the VM just to be able to defragment a 4 TB disk?!