Firstly, I'm sorry if this is a dumb question or if there are any misunderstandings on what I've written below. I'ts just that I've always read that The Great Depression had basically two major factors:
Factories producing too much and, due to low wages, there wasn't enough demand to consume it, which affect the stock market because their shares dropped.
Unregulated buying of shares due to the post-war economic optimism, creating a speculative bubble that would later explode.
And there are a lot of websites and even scholar books out there associating the overproduction to Fordism. However, some weeks ago, my History teacher told us that Fordism has nothing to do with it and told us that this a common misconception, but to be honest I'm not sure what explanation he gave us because I don't remember the exact wording, just some loose pieces of memories here and there. I was wondering about it so I decided to give it a search. However, when I've googled it today, I didn't find any reliable article clarifying if they were actually related or not, only contradicting data between different websites. They either mention Fordism as a factor, saying that its revolutionary method of production created stocks due to low demand and this impacted the stock market, or they just don't mention it at all and just mention the overproduction itself.
So what is exactly the relation between Fordism and overproduction? Was Fordism really the cause of overproduction or it wasn't it at all? And if it's not related to the issue, why did the overproduction happen and how did it begin?
Thank you a lot.
Fordism
Your teacher is right, Fordism/over-production isn't generally accepted as an explanation of the Great Depression amongst economic historians and economists.
A strong reason for thinking this is that economies are circular: if A buys something from B for $100, then B must have sold something for $100. So if wages were low, then profits (aka the return on capital) must have been high - or it's all going in taxes. Of course the rich do tend to buy different products than the poor or the middle class - Cadillacs instead of Model T Fords, but in that case we'd expect businesses to switch to providing more luxury goods, not shut down entirely.
What's more, Ford's production techniques lowered the price of goods drastically, a Model T FordModel-T fell from $850 in 1908 to less than $300 in 1925. I know of no evidence that working class wages saw any fall like that.
Finally, manufacturing is only one part of the economy. The 1920s were a bit before modern statistical collection, but services were estimated to be more than half of the US economy by 1929, and services are typically consumed when produced and thus hard to over-supply.
An unintuitive thing in economic history is just how big most industrialised economies are. The general rule of economic history is that "it doesn't matter" for an awful lot of "it"s. This is particularly true of the USA in the 19th and 20th century, a famous piece of work in economic history concluded that railways didn't make much difference:
that the level of per capita income achieved by January 1, 1890 would have been reached by March 31, 1890, if railroads had never been invented.
During the 1920s, there were a myriad of things going on in the US economy, the Economic History Association's website has a very long description of the things going on in the US economy then, that ranges from agriculture to energy to transport to finance to retail systems, as well as manufacturing. Increased manufacturing output was merely one thing here. Even though incomes may have been falling for farmers and Appalachian coal miners, there was a lot of other sectors where increases were happening.
As to why the Great Depression happened, this is a complex topic that many economists have attempted to explain.
The causes of the Great Depression are a hotly debated topic, but the mainstream view is that important factors were the supply of money, the US Federal Reserve's actions, or inactions, and the international gold standard. The sharemarket crash is not thought to be a direct contributor, similar falls have happened before and since without being followed by a Great Depression, though there are economic arguments that the sharemarket crash contributed indirectly in various ways. The Economic Historians Association's website has a more detailed summary of the US experience of the Great Depression and the theories around it at https://eh.net/encyclopedia/an-overview-of-the-great-depression/. Unfortunately these theories do get very technical fast. They generally agree though that the size of the downturn has to be explained by systematic factors across the economy, not by relatively small changes like improved production systems.
I hope this helps, sorry about the delay in responding, I spent a while thinking about how to explain the issues with the Fordism hypothesis.