My dad lived through the Great Depression. I remember that he talked about people carefully saving thread, not because thread was so expensive (or money so scarce), but because no new thread was being made, because the factories had shut down because the companies went broke. So I'm not sure I buy your interpretation.

This is a marxist-style crisis of capitalism, in essence:

a) business hires workers to make goods to satisfy demand

b) business overproduces to make sure they meet all the demand

c) business has 6-12 months of inventory, lays off workers

d) business can no longer sell inventory since workers don't have money, can't afford holding costs, dies

e) liquidator sells off glut of inventory, lowering prices and preventing new firms from entering the market

f) no new inventory is created since firms are dead

g) shortage arises, driving prices sky high

It's a bit like a wave oscillating in a container.

I'm interested in this; what stuff specifically was made too much of?

Like boots and shoes and clothes and pots?

Those are all directly applicable items of need - as opposed to headphones and phones and laptops and (name electronic product)...

So what items were a glut in ~1930 that would have contributed to this?

My skepticism tells me it was financial speculation, and not physical goods that had more an impact.

And even if I were correct, which I do not know, I'm amazed that there was enough thought in the space to create such a depression.

The phrase "money is the root of all evil" only exists for a reason...

"The phrase "money is the root of all evil" only exists for a reason..." And all this time I thought it was "love of money"