I’m not sure, I think its nice “eye candy” but doesn’t necessarily contribute to safety. Airliners are required to carry a TAWS-A system (E-GPWS) with a terrain display feature. Only the way information is displayed varies, i.e. more fancy on a G1000 with synthetic vision. Having this installed might also cause people become dependent on it maybe.
When flying IFR and following procedures correctly, thoroughly prepare and brief, effective CRM and Threat and Error Management you won’t need something like that. Its more important to prevent ending up in such situations in the first place. I think its more of a help for non-professional pilots and VFR operations where routes and altitudes are closer to terrain and obstacles and based on the “see-and-avoid” principle.