VR is actually amazing now. You just need a comfortable headset (the Bobovr M3 Pro is my favourite).
The graphics in some games are awesome, and I can watch movies in a full theatre environment on my sofa. I’m kinda sad it hasn’t taken off, because it really is great. I’ve gotten my whole family into it now, even my 88 year old dad.
The headache and nausea comes from the hardware not being able to render 90 fps at 90 Hz. If you can satisfy that then both conditions go away almost completely.
If you're really sensitive to motion you'll still get motion sickness when using locomotion instead of teleportation (moving smoothly with a thumb stick instead of just teleporting to where you want to go with a screen blank when traveling)
Yes, that's basically what it is! I read a lot about it back in like 2017 when I got my first VR headset. There are articles out there if you're interested in reading more.