Since the problem described in this issue should be resolved in a recent advisory, it has been closed.

For information on the advisory (Important: OpenShift Container Platform 4.14.0 bug fix and security update), and where to find the updated files, follow the link below.

If the solution does not work for you, open a new bug report.
https://access.redhat.com/errata/RHSA-2023:5006

https://github.com/openshift/installer/pull/7328
Should fix the issue

https://github.com/openshift/installer/pull/6496 is not merged yet.
As a workaround, the following steps were executed to verify destruction of service instance. This was successful.

1. Create a cluster as you normally would
2. Create a new Power VS Workspace after you deploy, that is named <infraID-power-iaas >
3. Run 'openshift-install destroy cluster ' command
4. Verify that the Power VS Workspace you created in step 2 is destroyed along with the cluster.

Tried verifying this with 4.14.0-ec2 build.
OCP deployment itself failed while trying to deploy without specifying a "service instance"in the 'install-config.yaml' file.
Error msg: FATAL failed to fetch Terraform Variables: failed to fetch dependency of "Terraform Variables": failed to generate asset "Platform Provisioning Check": platform:powervs:serviceinstance is empty.

Above error is caused because the code for creating the service instance has not merged yet. PR: https://github.com/openshift/installer/pull/6496
Dev has pre-emptively merged the destroy code.
QE cannot verify the fix now, need to wait until the PR for creating the service instance gets merged. FYI: jpoulin hamzy_redhat ahendre2