Cognitive dissonance causes discomfort because it disrupts our sense of
dependency
unpredictability
consistency
power

consistency

Explanation:

In psychology, cognitive dissonance is understood as the stress or discomfort we perceive when we have two contradictory or incompatible ideas, or when our beliefs are not in harmony with what we practice. This creates a great deal of discomfort because it alters our sense of consistency.

When we experience stress or discomfort from expressing two incompatible ideas, we will try to eliminate them or avoid the situation and information that may feed them.  That is, we will try to minimize the dissonance. To minimize it we can use various ways, such as changing attitude, changing the environment or adding new information and knowledge.