Typically, an app must be in the top 3 positions to gain the most organic traffic. For example, if your Android app is ranked 50th when searching for "best fitness apps" in the USA, it is unlikely that anyone will discover or install your app.
After optimizing your app by purchasing keyword installs for several days, if your app's ranking improves to the 3rd position, it will significantly enhance visibility and increase the chances of attracting organic traffic from search results.