It will add a lot more strategic diversity and interest to the game.
The problem is the techs in each line right now are all roughly the same. The different "ages" are arbitrary and meaningless. This should be changed.
By providing significantly more powerful buildings in the second age, and increasing the tech and production costs of such buildings, it would force the player and the AI to CHOOSE and PRIORITIZE according to their strategy. For example, if you choose the manufacturing choice, you would be forced to forgo the planet population growth path simply because you don't have the research points. Consequently, you'd be forced to leverage your extra manufacturing (which becomes inferior to higher pop path in the long run) into an early rush.
This would add strategic depth to the game.