Nintendo originally had plans for a VR experience roughly 4 years ago

While the Virtual Boy was certainly an experiment into some kind of extremely rudimentary VR experience, Nintendo Labo's VR Kit is Nintendo's first true foray into VR. While it took a few years of the Switch's existence for hte project to release, Nintendo actually came up with the idea roughly 4 years ago.

Nintendo had a plan for a VR experience before the Switch even launched, but that idea was put on the shelf for some time.
While there's no official word on why the plans were temporarily halted, many inside/outside the company believe it has to do with Sony releasing their VR headset, which was the first to bring high-end VR experiences to consoles. Sony running with VR could have lessened the impact of what Nintendo was trying to do.