There is a big difference in how the two games did city unpacking, though. In 6, most of the districts were locked behind that city's population, and multiple utility buildings were going into the town centre - the equivalent of granary, saw mill, and so on. So while they were decompressed, you also weren't getting megacities merging into one another by late antiquity. I agree that city unpacking is good, but I do think that Firaxis missed a trick by not having fewer available buildings and more restrictions on where you can place them in the early game. You should be gradually working towards a large metropolis through the ages, not start with about 80% of the building count of modern era already available in antiquity.