I made the mistake of thinking that satanists were just the elites.
Yes, there are elite satanists and they have the most power. But there are many, many more minions who are completely devoted to the cult who otherwise look and live like everyone else. They aren't famous and they aren't immensely rich or powerful.
Think of all those fake Qanon twitter accounts making WWG1WGA videos.
That they were able to keep it such a secret from the rest of us is an incredible feat. Of course, the threat of death to them and their loved ones kept them dutifully silent too.