That statement is a perfect summation of the series in general. I think you are spot on on your observations, and it is something that has always plagued the series. The game is just so different on turn 100 than it is on turn 0 and that change becomes exponential. Part of that is the design of the genre, you begin with nothing and grow into a powerful force. But the gameplay is starkly different. The game should find new ways to keep you engaged with the map into the later eras be that through increasing the colonization abilities or changing how you influence the world. I think it is inching that direction. The underlying systems for religion, trade, and loyalty are great ideas, I just think they need some more time in the oven to really understand how they interconnect and where they overlap. I do hope the devs keep that in mind as they add features, because the game really does revolve around the map and features that don't engage the player with the map should be avoided (even if they add historical significant or are super cool).