Book 1 Chapter 2.4 - Progressions should end on I

In this chapter, it says things like “By depriving the listener of the I chord for so long, when it finally does sound, the stable feeling associated with the I is magnified.” But then the chord progressions played as examples end before returning to the I chord. This would serve as a better demonstration if they continued into a resolution, even if the melody has to be stopped at that point.