This is short info from article "Why your ASO is not perfect?":
In today’s market, there is a general lack of information about how popular certain search requests are as app stores (App Store and Google Play) do not share this information. Perhaps part of the problem will be solved for the App Store with the advent of Search Ads from Apple. The service however, is not available for all countries, and also carries other functional loads, and is therefore not a tool for optimization.
Where does the bad data come from?
Such requests for information may be popular on the web, but unfortunately are not when it comes to mobile app stores. There are many reasons for this, for example, the average user is unaware that he/she can search for applications by their specific functionality. As an example, not everyone understands that it is possible to find applications for flower delivery or car washes. These markets are just beginning to develop, however, and in the future the situation will be quite different.
Unfortunately, many ASO-services do not calculate the frequency of search requests by using existing app store infrastructure, and instead, only use search request data from the Web (the author’s research was conducted on more than 100 000 search requests that were not published in accordance with fair competition practices).