I remember reading this for years before the dot com bubble imploded, years before the housing bubble impoded, and months before the market woke up to the fact

I remember reading this for years before the dot com bubble imploded, years before the housing bubble impoded, and months before the market woke up to the fact that COVID existed. (At least governments decided to print that last one away.) On a more serious note, the fundamental issue in the first two crashes was that the markets stopped being able to rationally price things. My view is that this doesn't always mean there will be an immediate crash. It just means that when the inevitable downturn does happen, nobody will be able to figure out the correct pricing for anything -- and so a correction turns into a catastrophe.