It can be good and at the same time bad depending with the plans set and the people responsible. On the good side, urbanisation opens lots of earning opportunities for the youth in a country hence boosting people's economic life. Also, it can expose people to modern life unlike the one experienced in the rural regions and good social amenities like hospitals and schools. Finally, it brings people together from different ethnic groups and share out cultures. This intermingling is such a good exposure for the people on the urban areas.
On the contrary there are side effects of urbanisation like congestion in the cities. You find people are crowded in a place traffic is still and this slows down work. Also, there's high living standards in urban areas because of congestion of people who compete to get jobs. You'll find there are less earning opportunities but people are more than excess. Finally, you'll find that crimes rates increase in urban areas due to lack of jobs.