City has its architectural character, but the similarities between cities are more obvious these days than in the past. In my opinion, one reason for this is the high price of land.
In most large cities, land is scarce and consequently it is very valuable. This has led to the construction of tall buildings which occupy only a small area of land while providing lots of floor space where people can live or work. Buildings of this type are made of concrete and steel and can be built comparatively quickly using prefabricated materials. They do not use local materials, such as stone, timber or brick, which used to give cities their individual character. In consequence many cities. now look very much the same and you might not know whether you were in Brisbane, Bangkok or Berlin when you are on the street.
While I realise that we cannot stand in the way of progress, I believe that cities should try to keep some individuality. For example, in Paris it is prohibited to build very tall buildings in the centre of the city, as this would spoil the overall appearance of the skyline.
Other cities have chosen to design unique buildings to ensure they look different. The twin towers in Kuala Lumpur or the Opera House in Sydney are examples of this approach, and I agree with this kind of initiative.
All in all, although it is regrettable that modern cities look similar, I tend to feel that this is unavoidable. However, it can be argued that, even if the buildings are similar, cities will maintain their own character as a result of cultural diversity, the terrain and the climate, which ultimately determine how people live.