60 hz in VR feels disorienting. I recently upgraded my video card to an RTX 3090, which allowed me to finally go from 90hz to 120hz using my Index. It was incredible how much the experience improved. I used to have a vive, and when I first got the Index the headset felt pretty similar. But once I improved the refresh rate it was a night and day difference in feel.

Motion Sickness. You can try it with FPS.

For me it is funny because the more realistic or better the graphics, a higher baseline frame rate is required. So my brain sort of work great with Counter Strike at 60 Fps, where the graphics are low Res and not any good by modern standard. Once it gets to very good / realistic level my brain sort of half interpret it as real thing. And expect "real" world motion. At this point 120fps feel so much better while 60fps cause me headache.

If we are not limited by computation constraint I would want to push for even higher frame rate rather than higher resolution.

You need a high refresh rate to keep convincing your brain of the illusion. If you dip down to 60hz and below, VR sickness can be a real problem.