If you gain local privilege escalation on some workstation user, you can gain access to credentials of user(s) of that workstation which allow you to impersonat

If you gain local privilege escalation on some workstation user, you can gain access to credentials of user(s) of that workstation which allow you to impersonate that user throughout the network. If it's a privileged user, then you can move to many more workstations, if it's a non-privileged user then you may be able to use their normal access (email, network shares, access to internal applications) to try and trip some privileged user into compromising their workstation in a way that you could not from the outside. Or you can wait a month until some tech support person logs in to that workstation and you can steal their credentials.