VHS is opt-in because it doesn’t just tell you who is streaming, which is public, but also gives you minute by minute data of who the viewers (who have opted-in) are, which is data that is not shared or obtainable through any other means.
If you don’t want to do coding and simply want to see who is live with your game you can just go to the Twitch page of your game and see who is live, and just refresh the page periodically. Notifications for when someone goes live though does require some coding to be done.