There are several advantages to using diction in writing and speaking:
Clarity: Diction helps to ensure that the writer or speaker is communicating clearly and effectively, by choosing words that are precise and appropriate for the context.
Concision: Using appropriate diction can help to convey a message concisely, without unnecessary wordiness or jargon.
Tone: Diction can also help to establish the tone of a piece of writing or a speech, whether it is formal or informal, serious or lighthearted, etc.
Emphasis: Carefully chosen words can help to emphasize certain ideas or points, drawing the reader's or listener's attention to them.
Style: Diction is an important aspect of style, and can help to make a piece of writing or a speech distinctive and memorable.