Ever-increasing improvements aren't required; the eye has a (more or less) fixed resolution. In fact, HMDs with extremely high resolutions already exist, e.g.

Ever-increasing improvements aren't required; the eye has a (more or less) fixed resolution. In fact, HMDs with extremely high resolutions already exist, e.g. the Varjo VR-2 Pro and the XR-1, they just cost an arm and a leg. In a few years we'll get them at consumer-level prices instead of having to drop $6-12k.