I'm not sure this is true. I know of several communities without strong regulations on what can be built (beyond perhaps size limits), and they tend to be pretty interesting. They also tend to develop their own individual character, due either to engineering limitations or social mimesis.

For example, Japanese houses are pretty disposable, but you can build more or less anything you like. (Here's a great article on it. https://urbankchoze.blogspot.com/2014/04/japanese-zoning.htm... ) If you combine this with the fact that Japanese depreciation rules promote 30-year disposable housing, you get a lot of very interesting homes. The result is that a ridiculous fraction of the interesting houses you see on archdaily are Japanese.

Or if you look at modern wealthy residential areas in north Delhi, you get a lot of interesting buildings. The neighborhoods again have their own unique character; it's a lot more heterogeneous than typical US suburbs, but it's clearly got it's own character. I can't find many pictures online, but I'll try to take a few next time I go.