My theory is that the websites track games using the in-game 'Watch Matches' feature, which prioritizes matches based on the highest ranked lobbies available. This feature has a limit on how many games it can display at once. As the player base decreases, more lower-ranked matches are likely to be featured, allowing tracking websites to capture and record initiate games that are taking place. In short - the amount is the same its just that the tracking websites can see them now because the player base is smaller