Currently, the Ai makes no real effort to expand it's empire after colonization.  It doesn't know how to use culture or alliances, and the military Ai is plagued with issues. Those things all contribute to the 'static effect".  The human player actively tries to expand their empire.  The Ai's stick to their provincial territories and do not.  This means once the human player gobbles up a few planets or small empires, they can't be stopped.  

The game is about expansion (it is one of the 4x's after all...).  If one side does it and the others do not, the one who does inevitably wins.

What needs to get fixed to solve this problem?

1) Rework the effects of alliances to make them more effective.  Make their effects well documented in game, and teach the Ai how to use them.  Specifically, in response to when one faction (human or Ai) becomes a dominant force in the galaxy.

2) Teach the Ai how to use culture as a tool to counter to dominant culture effects and as a tool of it's own empire's expansion.

3) Military Ai fixes:

- Remove the 1 attack/turn limit and allow it to move after an attack

- Teach the Ai to use the population slider when building transports

- Teach the Ai how to use more than 1 transport per fleet 

- Teach the Ai to protect captured worlds

- Rework ship blueprints to have more engines, and increase priority of engine research, especially in large galaxies.

Granted some of that can be done with 3rd party mods, but a lot of it cannot, and I would argue should not have to be.  GC3 has been sold as a 4x game, so there should be some eXpanding going on in the galaxy besides that being done by the player.  

Please give us the dynamic, changing, evolving galaxies that should be hallmark of this kind of game.  I want to see empires taken out before I even find them.  I want to see multi empire alliances that are supportive and effective.  I want to stumble on an empire mid game that is more powerful than my own, and I must adjust my strategy to deal with it.