I very much approve of the idea of making certain historical events or epochs have more impact on the game. Anything so game-changing would have to skirt the problem of "Civ A has invented guns and railroads, so Civs B, C, and D are just completely screwed." As is so often the case with games based even loosely on the real world, we actually want the game to be even, balanced, fair and suspenseful, with ups and downs for everybody, right up to the end. We can see how scared the devs were of making Golden Ages and Dark Ages very meaningful. Somehow, the game needs to retain each civ's accomplishments of previous eras as they move into new eras. If the real world were a game of Civ VI, the United States went on a tear during the Atomic Era, but does that mean we're winning the entire game, over civs like Persia, Greece, China and France? For Civ, the desirable answer to this question has to be "Not necessarily." To use a soccer/football analogy, the game must maintain a season-long league table, even as teams win and lose matches, and go on streaks where they look either invincible or hapless. Your 4-match winning streak early in the season still counts at the end, you get to keep those points; and even if you couldn't seem to score on an empty net in the first few games, you can still try a new formation or get a new player at the transfer window.