Understanding the Extract Data Tool: Exhaustivity Explained

Extract Data tool I'm trying to better understand how the Extract Data tool works. In the doc and when asking @help, it's seems like Extract Data is able to ensure exhaustivity (like Include Data) while not being limited by the context window (like Search)... it seems impossible to me but I don't find more precise information about it. Without knowing this I have a hard time trusting the outputs of this tool (even if I see that it's indeed way more exhaustive than Search... but still, is it 90% exhaustive or 100% ? I'm not sure...). Is it because we just fill the context with the json objects resulting from the data extraction that it takes less space than including everything from the source ? In this case, we still do not guarantee exhaustivity, just that "more data is processed compared to Search" and we can't trust the output when it says that for example "68% of tickets says XYZ". It is still 68% of tickets processed, but not 68% of all existing tickets if there are a lot of them. Thanks !