Many of them needed to be used in large factories. Many were steam-powered. Most people could not afford to buy these machines, so they went to work in factories. By the late Industrial Revolution, at the end of th 19th century, factories started a new way of building things, the assembly line. On an assembly line a good is moved along a long line to be assembled or built.
Workers stay in one place and do one job.
As the item moves along, the workers add whatever part for which they are responsible. By the time the item reaches the end of the line, it is finished and ready to be shipped to market to be sold. This was much more efficient than a cottage industry. In the cottage industry, one person, or a small group had to complete each part of the making of a good. Let's say that a person was building cars in his or her cottage, or in an early factory.