The service connection point is a fundamental role, but it's still optional. Why, though? The administrator might install it during server deployment or after. It can be removed anytime and the server will continue to work properly.
The role connects to Microsoft Cloud service and checks for any new updates that might be applied and whether a new version of the system is available. This role works under two modes. One is where the system checks for updates automatically and the second where it needs to be triggered by the administrator manually. The mentioned role is needed also for mobile device management when using Microsoft InTune (it replaces the older, already depreciated Windows Intune Connector role) and to manage on-premise devices with Mobile Device Management. This role is installed for the whole hierarchy.