Maybe because it's still experimental on your Q2? You really are not missing anything with standalone mobile VR games imho. Just heats up your headset and reduces battery runtimes. If you think you are wrongly missing out, contact Oculus Support and start a v33 ticket.
If you use Link or Air Link you should be able to select a 120Hz option with your Oculus desktop app device/graphics setting. Even with my rtx3090 I don't see much point going above 80-90Hz refresh rates because 120Hz requires lower graphics settings for most complex PCVR games/sims.
i9 13900K water cooled, RTX4090, Z790 MB w/wifi6e, 64Gb 6400 ram, 2x2TB SSD, 1000W PSU, Win 11, QPro, Q3, w/Link and Air Link, Vive Pro1 with 2x2.0 base stations, Etsy lens mod and Index Controllers
Today my quest updated itself to v34 and FINALLY I got the 120Hz feature. So they kept their promise that at some point in time you will get it. At least it proves that it's not a hardware related issue like some suspected. Let me know if you got it also together with v34. I'm very curious if they solved the issue now for everyone.
