The only time SVT would be beneficial is when deviating from published instrument procedures, even those mountainous airports you speak of nowadays have RNP-1 departures and arrivals, RNP-AR approaches. It is very seldom that an aircraft unintentionally wanders off track nowadays.
Question becomes, what do you want to do with information presented by SVT? Its not allowed for navigational purposes. Should you run into terrain you would have the FLTA trigger, SVT or not. In both cases you are required to level the wings and fly the exact same terrain escape maneuver. In case the aircraft climb performance is insufficient and the “AVOID TERRAIN / OBSTACLE” (if installed) is triggered a top down view as provided by the terrain display system would be more useful than SVT.
Situational awareness is already excellent in a modern airliner even without SVT. At those kind of CAT-C airports special training and briefings are required and interestingly the incident / accident rate is very low at these kind of airports because of this. A HUD is a different story, with HUDLS you could take-off with lower RVR and continue CAT III approaches by hand, even with an engine failure etc. it actively improves safety and saves money for the airline by preventing delays and diversions.
Sure CFIT accidents happen, the two examples you provided are pretty old airliners. Cockpit design, terrain displays etc. have greatly improved since then. I don’t remember when TAWS-A ((E)GPWS) was first introduced but it must have been around 1997? I could be wrong but I believe both accidents were before introduction of (E)GPWS which brought forward looking terrain avoidance capability, premature descent alert and terrain display systems into cockpits. So the question is, how useful is SVT in improving SA and avoiding CFITs over a top-down terrain display.
Edit: according Skybrary Honeywell introduced (E)GPWS in 1997.