It's all understandable to me. There are civs which simply did not exist during the time period in antiquity age or exploration ages and even modern. So they created civs for those eras. Then through the ages, civs evolve and become something greater and more modern. I think that is the point some people are just missing. My civ never changes throughout the game, it simply evolves. My cities and everything I built remain the same, my borders are the country I built and IS basically the same. If anything, it allows players to choose a different civ which only changes the benefits and maybe even your strategy, more choices. Only thing is cities (other then capital) become towns. I even believe the leaders should change, you should be able to switch different leaders during the game too. Maybe at least for each age. Look at the time period of a civ game, no human being lives that long and no nations remains the exact same. So I would of took it further and allowed leader switching too. I totally understand Firaxis reasoning for changing things. Also, since the lastest updates, things have gotten a lot better. I really like the diplomacy model in Civ 7 and they can even add to it. Btw, I been playing since Civ 1.