Sure, it is. People often move every 3-15 years, while staying in the same city (or sometime leaving for another city). This is much easier with renting where you just have to take care of finding the new flat, rather than also selling your old flat.

People usually buy a house or flat only when they are very good situated and are founding a family. And even then most prefer renting simply because you have to take care of less things (owning a house can be quite time consuming).