This, however, is wrong. Great Literature works survive as such because they prove relevant to every new generation. When they don't, they very quickly become forgotten or relegated to "famous back then, known mostly to scholars nowadays". Great Literature works that retain their high status over many hundreds of years usually have done that by having something relevant to say to every generation in those centuries; sometimes there're gaps of obscurity and then rediscovery, but those are the exception, not the rule.

this was true until Public Schooling became a standardized system. Consider how long it took for Latin to go from being mandatory to being something almost completely forgotten.