Why did the majority of Indians live in small towns and villages 7 decades ago?

70 years ago, things were not as they are today. Most of the people were into agricultural activities. There were not many industries and cities had not grown or advanced. People live in towns or villages due to thier livelihood being dependent on agriculture and small scale industries such as handicraft industries. The line of progress was flat and low unless slowly and gradually large scale industries such as iron and steel industries, heavy machine manufacturing industries, etc. were established and opened up opportunities for employment and  giving birth to advanced technology leading to multiple professional jobs as it is existing now. Slowly the cities developed in and around these industries. The homes and houses were much better and comfortable than towns and villages and facilities of education and healthcare was available in cities and hence people slowly started migrating to cities, and getting a better job than working hard in the villages.