There are a number of benefits that can come from urbanization.
First of all, urbanization can improve a country's overall economic prospects. This is partly because an economy can benefit from having a large number of people together in one place. This allows factories, for example, to have a large work force from which to hire. It also allows there to be many firms that act in a symbiotic relationship with one another (in other words, you can have a big firm be near to its suppliers and work closely with them). Because of this sort of thing, urbanization is often linked with economic growth.
Second, there can be benefits to the lifestyles of the people in the cities. Cities are much more likely than rural areas to offer cultural amenities such as museums that give people options for what to do in their leisure time. Cities are also able to provide more educational opportunities than rural communities can.
Finally, there are those who argue that cities are better for the environment. The argument goes that people in cities have to drive less, can use mass transit more, and generally have smaller houses and yards. These things mean that they use less energy than rural people do.