I have both…a 43” 4K HDR1000 monitor and a G2. I’d say both are needed depending on the flying you like to do.
If I want to be a computer operator 6 miles above the haze in a CJ4 or 747, then it’s 2D monitor all the way. Fiddling with all those thousands of tiny buttons is just easier in 2D and that’s all you’re doing when flying a tube anyway.
If I wanna sight see in a xcub low and slow, then VR is the best experience and totally different than piloting a monitor. It has gotten better lately with tweaks and revisions to openXR. It’s smooth enough and being able to just look to the side, or stick my head out the window and look down at something is amazing. Landing is so much easier in VR. You can feel it sink when you let speed get too slow, and a curving short final to a perfect touchdown is no sweat. But it costs and you need tippy top hardware for now.
With all due respect to the track-ir or iPhone head tracking guys, it’s not even close. I’ve had track IR, and tried phone tracking. No comparison at all.
It’s like going from keyboard and mouse controls to a flight stick and throttle. It’s that different.