Keyword tool volume rarely matches your traffic because the two measure different things: volume is the size of the market, and traffic is your share of it. The tool estimates how many people search the term each month across everyone, and says nothing about how many of those searches reach your page. The gap between the two isn’t tool error, it is the chain of filters between a search being made and a click landing on you.
Walk that chain. Of all the searches the tool counts, a large slice never reaches an organic result at all, because the answer sits in an AI Overview, a featured snippet, or a knowledge panel, or because an ad takes the click; on Google, more than half of searches now end without an organic click. Of the clicks that remain, they split across the whole results page, and where you rank decides how thin your slice is: the top result takes a large share and it falls off steeply, so a position-five page sees a fraction of what the top spot does. Even at a fixed rank, your title and description decide whether an impression becomes a click. Each step takes another cut out of the original number.
So the volume figure is a ceiling, not a forecast. Treat it as the total demand available, then model the capture beneath it: estimate where you can realistically rank, what the SERP leaves for organic results after its features take their share, and how your listing is likely to draw clicks, rather than reading the tool’s number as traffic you will receive.