What's the point of the ages when players just speed through them?

Is there a way to make the AI start attacking/defending in the dark age? To me it seems the Dark Age and the Feudal Age are completely unused and rushed through at the beginning of the game. Barely anyone builds units through these ages and while this is more efficient and competitive it seems to cut a lot of gameplay, I'd like to experience these ages more without having to limit the game to be set only on these ages.

Is there a mod or something that stops the AI from advancing to the next age for the next 20-30 minutes or something like that? I'd like to have some battles with retarded units goddamn it!