It seems that travel guides are not really the starting point for finding a destination; it's often the practical value after the initial inspiration.
We don't take a guide to dream of a place, we consult it when we already have a spark of the idea, often from a friend or a TV report.
The guide is more for concrete planning, to check if it's feasible, and for details once on site, especially without internet access.
The pattern I see, but can't yet prove with numbers, is that inspiration first comes from others' experiences or entertainment, and the guide comes afterward, as a confirmation tool.
If sales of paper guides continue to decline while travel influencers gain popularity, that would confirm this intuition.