Many apparently useless things contribute to situation awareness, and this is exactly what SVT will do. As an example, it's true that when ATC gives vectors to a pilot, it takes responsibility of terrain separation. We can crosscheck that with MSA and MORA, but the SVT will make it feel more comfortable.
The list of things that are not "needed" include HSI, RMI, TCAS, and to some extent GPS and autopilot. Would you fly without them ?