Example: Guns. Before the Industrial Revolution (IR from here on out) it took a master gun smith and his small shop a few days to turn out a gun, He could create a few dozen guns a week. AFTER a gun factory could make dozens or hundreds in a week. Not only that, but it lead to interchangeability which made the life of armies that much better by making it easier to repair weapons in the field.
The price of guns came down with the development of mass production, the quality did not go up at first, but did later as machines were developed that could be more accurate than most craftsmen. This made larger armies much more affordable. Imagine arming the 50 million soldiers in World War 1 with just gunsmith shops.
This same thing applies to food. with the IR, surplus food was canned, boxed, preserved, and transported to stores. Food lasted longer, was more abundant, and cheaper.
Factories are in cities because you can centralize the labor force, transport of input material, and deployment of products. This labor force moves to the city to work. Living in a city is MUCH different from living in a country farm. Urban and rural cultures are very different. Rural being more spread out doesn't have to deal with in-your-face strangers who are not of your culture, creed, or customs living next door to you, often in cramped tenement housing.
This dramatic urbanization and concentration of labor lead directly to reform movements that swept the western world in the late 19th and early 20th centuries. People were willing to turn to stronger and more centralized states to solve problems that seemed too large to solve on their own or as small groups.
Another issue is how people worked. Generally most people before the IR were farmers. They worked on a farm they owned or leased (some were also still serfs, like in Russia), and as such they were effectively self employed businessmen. They set their own pace of labor, planted their own crops and sold the excess to pay their rents and taxes and buy goods they couldn't make themselves.
but with IR, most people ended up as employees of others, by the end of the IR most were employed by "Faceless" corporations and they felt highly disconnected from it. the idea of Worker vs Management developed.
The entire idea that it is normal to get a job, rather than be a farmer or craftsman is an IR development.
I hope this clears a few things up for you