Ever since i got my Rift S 2 years ago on my 8600K 1660 Ti 16gb rig, it was running as smooth as butter, but sometime 7-9 months ago there was an update to the drivers and it introduced inexplicable tiny stutters that are really noticeable, especially in Beat Saber (it would literally make me mess up every time), so i ignored the issue for the longest time and avoided precise movement vr games. Just today i upgraded my gpu to a 3070 and reinstalled windows to a fresh install, update every single driver i could find. The issue persists. I don't know if it's the driver or my cpu is no longer enough for VR.
Same here with my Rift S, but i don't think it's an Oculus exclusive issue (at least not in my case) because i've tested a Valve Index a few days ago and had the exact same stutters on my system. I think it's an Nvidia driver issue and it seems like they're working on it.