I agree Ed. I actually have thought the game would lend it self perfectly to an entirely different concept of victory - not one of adversarial win/lose as we've become accustom to in games, but one of success level.
Each player would be given, or perhaps even allowed to choose, one national objective from a list. How well a player is doing relative to that objective would then be judged by the game. Judgment could be numerical or categorical: highly successful, successful, marginal, unsuccessful, abject failure.
National objectives could be all sorts of things - the only limit is imagination:
Maximize global territory/population (basically the objective in the game currently)
Capture most resources of a particular type (metal, water, ...).
Capture most hex perks
Exterminate a certain culture (slavers, raiders, hunters, ...)
Maximize civilization level
Maximize technology level
Maximize international relationships with other nations
Maximize recovery of ancient artifacts
Maximize population/worker happiness
Minimize the military-to-population ratio
Maximize treasury cash
Dominate global trade
... just to toss out a few off-the-cuff ideas ...
Players would not know each other's objectives (at least not without some sort of espionage effort).
That would make for very interesting games being much more difficult to predict what other players will do.
Multiple players could be successful or highly successful, or every one could fail. Victory would the one who had most success or failed least badly
I do not see the AI being able to do any of those. So it would be a player-only thing.
Wich is fitting given how much difference there already is beween AI and Human players.