Assuming a Google Apps Script has been granted authorisation by the superadmin account to manage Drive files & folders, can this script perform operations on other-users Drive folders & files, or the authorisation is limited to superadmin-specific files & folders?
In enterprise applications you may want to programmatically access a user's data without any manual authorization on their part. In G Suite domains, the domain administrator can grant third-party applications with domain-wide access to its users' data — this is referred as domain-wide delegation of authority. To delegate authority this way, domain administrators can use service accounts with OAuth 2.0.
While the above quote says "third-party applications" it also includes in-house applications.