I suspect VT-standards-related hardware (and software emulators) survives because the protocol can be implemented without fear of getting dragged into court for licensing fees. Whereas if you wanted to implement NeWS (or Display Postscript) even today, you still have to license it. There is an informal mention that NeWS had too many third-party components to ever open source. [1]

[1] https://github.com/IanDarwin/OpenLookCDROM