both two questions are related, all ancient developed civilizations are near sea to have easy access to trade. no its not about fish, it is about trade. simply trade.
yeah it would remain same in 3000 years. are you thinking of a plot of your new fantasy book? or are you 5 years old? yeah it would remain same in 3000 years. yeah
*can you really imagine a culture that would be same in 3000 years? can you? is it possible?