I wonder how this is any different in any other places?

For example in the USA, iconic places like LA, Miami and Chicago also are extremely boring and and look similar street by street. Especially LA. After hearing the hype for about 3 decades visitors will just realize it's extremely large ghetto connected with 8 lane highways.

Haven't been in Shenzhen myself but I used to live in Shanghai and visited Beijing and Suzhou often, all of which were really interesting places and didn't "lack character".