VR games, and simulation games tend to have high single-core CPU speed requirements for smooth play. Mostly though this is due to outdated engines (in the case of sims) or inexperienced/indie devs using premade engines like Unity and Unreal in a way that loads mostly a single core. Some tasks like physics, sound, texture loading is pretty easy to put on separate threads but thats usually a small fraction what bottlenecks a CPU in a game.
Eh, my i5-4440 had zero trouble running current VR games at 90hz, including while doing other things like playing Spotify or running music from a web browser, or even streaming and recording.
