For what it’s worth…
My wife (age 59) grew up, in the late 1960s and early 1970s, primarily wearing clothes that her mother and her grandmother sewed on their sewing machines. Strictly speaking, they didn’t need the sewing machines, because, yes, store-bought clothes were available.
However, her family was not well-off, and sewing clothes, at home, allowed them to stretch their clothing budget much further than it would have gone buying clothes at a store. So, from the standpoint of balancing a tight budget, yes, they did need those machines.