Name a single game that makes use of 3D TVs like you can for PhysX.TVs dropped support for 3D movies long ago. And nVidia dropped support for their 3D vision, too.
Most people don't care about PhysX because it only affects old games. That doesn't mean it's not relevant to cover.So GN has not covered it because "it was essentially dead". Ironically this would have been a topic in his 5090 review, but i guess when you dont care about it, it would have been not worth it to check the support...