The concept of a "classical period" is generally agreed to be Eurocentric but it also has some validity when looking at other areas. For example, the Late Zhou period, by which I mean the Spring and Autumn and Warring States periods, has a lot of similarity to Greece in the Chinese cultural consciousness, and Qin and Han have a lot of similarities to Rome. India is a little bit more complicated, but the Gupta is generally considered to be the "Golden Age", although there is always some concern that this is a European imposition given that much of India's early history was first systematized by British antiquarians.

The concept never works one to one and we always need to be careful that we aren't imposing false narratives on the past, but there are general tendencies to go "back to the basics" in cultural history, and this constructed "basic" is what later emerges as "classics".