The journey never improved. It only worsened. Actually, the trip didn't change, but Khan's mental state did, spiraling down a rabbit hole of endless loneliness.
Khan had already gone through something similar before reaching Coravis. In theory, that first experience should have been worse due to its length and lack of clear directions, but Khan found it incomparable to what he was enduring now.
There were multiple reasons for the greater impact on Khan's mental sanity.
First, as aimless as the first journey had been, Khan could at least indulge his curiosity. His mission required him to explore anything that appeared on his scanners, making him feel like a proper scout, adding details to a vague map, and connecting long-lost ancient clues.
