Well, the question is scientifically valid. My theory predicts that when the next major recession happens, Vanguard and other passively managed funds will beco

Well, the question is scientifically valid. My theory predicts that when the next major recession happens, Vanguard and other passively managed funds will become dramatically less popular (which will amplify the fall), and actively managed funds will come back. Your theory predicts that none of this will happen when recession strikes. So, I propose we wait and see. :)