Having good diction is an essential part of writing well, no matter what kind of writing you're doing. Diction is the key to developing your style, tone, and point of view.

Pedantic diction. This is when a writer is highly detailed or academic in their writing. Words are chosen specifically to convey only one meaning. It is sometimes used in literature when characters speak in a highly educated manner, as in F. Scott Fitzger

Good diction is important across all styles. However, for some styles, it is much sharper, for example, Classical and Musical Theatre. Whereas in other genres you can get away with less crisp and pronounced diction.