What feature or improvement would you like to see?

Service account impersonation is more secure than using a service account key because service account impersonation requires a prior authenticated identity, and the credentials that are created by using impersonation do not persist. In comparison, authenticating with a service account key requires no prior authentication, and the persistent key is a high risk credential if exposed.

https://cloud.google.com/docs/authentication/use-service-account-impersonation