The most common reason is that your advertising budget is being consumed by ineffective keywords. When you cram every keyword you can think of into your ad account without strategic categorization, your budget gets spent quickly in a short time and fails to reach searchers with real demand. There are two directions to improve: First, research which keywords and ad copy your competitors are using in your target markets. Second, analyze the actual search behavior of potential customers. Once you understand these two things, categorize keywords based on customer pain points and write corresponding ad copy for each category. This way, when consumers see your ads, they'll feel "this is exactly what I'm looking for," which increases click-through rates and inquiry rates.