I think people really underestimate what the difference between "winning" an Age and winning the game might be. When there were no Ages, you always should do whatever made you win the game itself harder/faster. Now there's multiple strategies for doing so: focus on winning this Age's unique conditions (which may not be relevant to winning the game) so that you can get bigger bonuses to the next Age, or start planning ahead for things that will win the game in the long run, or somewhere inbetween. Players who are "ahead" get more bonuses for the next Age, but they were ahead in areas that may not normally translate to winning the game. The things that usually translate to winning the game (science and culture progress, general infrastructure) are getting soft reset each Age, which is exactly the type of slingshot mechanic we actually need here.