The optimum population of that island is 2.5 million. I should know because I lived through that era and everything was just nice.... a true goldilocks zone.
IMHO not only the population number matters. The type is also very important to maintain the identity.
Also in those era, things were more scarce and to me is a good thing. Progress is not always a good thing.
Having credit card was a privilege.
Even in the fashion arena, was not easy to stand out among the crowd, unlike now, every youth can imitate each other and their idols easily. So many magicians now, so many musicians now.
And many more. Uncle can no longer stand out among the crowd.