If a Virtual machine has a snapshot taken and then a VMDK is removed from the VM with the option "Remove device and data" the VMDK remains on the datastore even if the VM if deleted subsequently.
Sample Steps to Reproduce the Issue:
vSphere 7.X, 8.X, and 9.X
This is by design and intended to safeguard against accidental data loss.
If the hard disk requires complete removal it can be done manually via the vCenter UI.