I was trying to allow a non-admin role to view license usage (Settings → System → Licensing → Usage) by granting the privileges nx-licensing-read and nx-metrics-all. This results in the license usage view being visible to the user but empty.
Looking at the network requests using the browser's developer tools shows that clicking the Usage tab triggers an api request to /v1/monthly-metrics, which is being denied (403 Forbidden), resulting in no content being shown. I would have expected the privilege nx-metrics-all to grant access to /v1/monthly-metrics.