The Chinese and Egyptians are an interesting case in this because they had one of the earliest written scripts (or rather tradition across generations to impart and carry information) and it was spread over long surviving/thriving timelines.
But then Egyptians lost the linguistic capability and lost their history even though they had archaeological structures all around them.
Language IS Culture. Literally.
There is only so much oral tradition can do. Even if it survives the population scale that carrier it becomes smaller and smaller and the cultural pressures from the majority overwhelm or dilutes the narrative 1000 years later. This happened in India. People forgot/evolved their ancestry even if there were a gross minority of class who remembered their class’s origin myths in a certain way.
From a purely reductive and spare understanding of human flourishing, this is irrelevant trivia.
The destruction of the Bamiyan Buddhas was no great loss. They were stone. Carved by man. That might be a Benthamite view. It would be a Salafi view.
But most people don’t think this way.
One of the themes of Toby Wilkinson’s The Rise and Fall of Ancient Egypt is that the temple institutions persisted over thousands of years. Even as dynasties turned over, the temples maintained a link to the past. Though many of their cultural characteristics were disappearing by the time of Ptolemies the Egyptians of this period still exhibited continuity with their ancestors. The hieroglyphic system actually was used down to 400 AD. The last inscription is dated to 394 at the temple of Philae. Philae continued in operation down to the 6th century, before it was closed by Justinian.
Other documents indicate knowledge of the hieroglyphic system into the 5th century AD. But the destruction of the old temples, the old customary religion, was the death of the old history and identity.
The Chinese continuity is striking because it is true that down the last years of Imperial China in the early 20th century the literati could access the entire corpus of Chinese though back 2,000 years. Dynasties fell, but unlike the West, there was no rupture with antiquity.
The case of India is interesting because I would argue Hindu Indians have maintained continuity with the civilization of India as it had matured in the centuries around the invasion of Alexander the Great. The Brahmins have maintained Vedic texts and the Sanskrit language. Those from the Abrahamic traditions sometimes contemptuously refer to Hinduism as “pagan,” but there is some truth in this, insofar as the religion grew and accrued itself organically from the native cultural traditions.
Today China is promoting “Confucius Institutes” as part of its “soft power.” Chinese who lived in the late 1960s would find this very strange, as they had abolished Confucius and were overturned the culture, the civilization, of China. But such tumult is not sustainable. I wonder if we are going through the same thing in the West. If so, perhaps we too will be promoting Plato institutes a generation from now?