There are many reasons why people believe that they need to have the solution or the answer. Examples are the need to feel or show competence, the sense that this is how they will be perceived as leaders, the impression that they can’t get support from others or the idea that this is how they can control the situation.
The immediate impact this has on the relationship with others is that it reduces the amount of communication exchanged. Curiosity and the quest for information are replaced with quick judgment or a flow of information. Listening to the information others share seems less relevant, leaving them unheard.
It results in frustration for both. The ones wanting to contribute who can’t do so. The ones advocating that they have the solution who don’t find themselves being followed.