Share Screen
Macs on your network that share their screen show in the sidebar's Network list. Right-click one and choose "Share Screen…": the system's Screen Sharing app opens and asks for the account on that Mac. The same item is in the context menu of a share mounted from such a Mac.
Connect to Server (⌘K) accepts a vnc:// address for a computer that is not in the list.
The app only hands the address to Screen Sharing; the session itself, the sign-in and the permissions are the system's. "Share Screen…" is offered even when macOS does not let the app look for screen sharing on the local network; the connection then simply fails if the computer does not share its screen.