Yeah thanks, I think that sort of sums up many of the issues with ages, but also with the basic resetting that Crashdummy mentions above. I think the problem is that Firaxis wanted players to be able to play shorter games starting in any one of the ages, and so built a system and a game that works in that scenario. Therefore you can start in exploration and play a similar game to the one if you started in Antiquity.
I think is a fundamentally bad decision, because the game should not play in the same way in all 3 ages, and it is simply too punishing to reset so many things at the end of an age. It feels bad.
I have a very high confidence that the number of players starting games outside of Antiquity is incredibly low, and so this decision essentially wrecked the game for no reason.
Really a civ game is about using the early ages to build up your strategy, and then use that foundation to move towards a goal in the next age. That doesn't really happen very much in Civ 7 because you spend much of your time just redoing many of the actions you took in the previous age. That is not a fun interaction. I don't mind overbuilding, but if all I am doing is putting a slightly better science building on a now defunked science building (because that makes the most sense) then how is that fun?