Certainly there are many underlying factors, but a massive change in consumer behavior with a somewhat open-ended timeline is itself much worse than many of the other issues in the economy.
Like in Sneakers:
People think a bank is financially shaky
Consequence: people start to withdraw their money
Result: Pretty soon it is financially shaky
In other words, stores running out of things and/or online sales being strong aren't, by themselves, the cause of major market movements right now; it's speculation about what'll happen tomorrow, and making sure you don't own any of the stocks if & when it tanks. Which incidentally causes the stocks to tank.
Amazon for instance started running out of generic Tylenol and other items you're recommended to have on hand yesterday.
I was putting stuff in my cart Saturday only to have it be unavailable for the forseeable future by Sunday.
Online merely lags behind brick and mortars. They'll probably have more stuff available since you aren't browsing but searching for specific things, but for things everyone thinks they need, they won't be doing much better.
Everyone knows about the student debt crisis. Everyone knows that public companies were borrowing to pay for stock buybacks. Everyone knows about the rampant de-regulation and rent seeking. And nobody thinks any of these issues will be addressed in the coming years.
It's going to be the 1980s all over again.
Because the small subset have a lot of motivation to advocate for the status quo, and each individual outside the subset has only a small motivation to advocate against it.
Something would have popped the bubble, and I’d argue the real cause of the start of the downturn was OPEC and the bottom falling out of the oil market. Then COVID set in and made things a million times worse, making a quick recovery nearly impossible. That’s what will be remembered by lay people, while experts will hopefully remember you can only pop a bubble if there is a bubble to be popped. And OPEC/COVID didn’t create the bubble, they just popped it.
1) Europe was a powder keg. The assassination was a single item is a list of reasons a war happened.
2) The escalation of war to involve multiple countries happened only after multiple attempts at de-escalation. Saying generally that leaders wanted to go to war is a massive oversimplification of the start of the war
Also, consider that there are always people (especially on HN) predicting stock market crashes. I'm not sure it makes sense to ascribe the ability to predict the market to people who happened to be right.