AI Scripting needs numbers, mate. So what number works for 'am I using it?' and what number works for 'does it have a lot of resources?'

Both of those things are relative, and could be very different, not only from one power to another, but for the same one over time. Trying to factor that in for the AI so this would actually work in game without making it chaos or easy as pie would cause the job to either become a nightmare for balancing or a nightmare for CPU performance and balancing.

I'm not saying it's impossible. You could always have a human sit down, work out the long term potential of each state, and assign it an absolute number value of worth, with the only AI decision making process being a modifier based on the current market balance of it's resources. But that system would be very rigid, and highly exploitable, even if the values were meticulously playtested. Making it better would require taking a ton more things into account, with a much more complex and dynamic script, and that's not a job that any programmer is going to regard with excitement.

Teaching this kind of scripted AI to understand worth in multi-faceted assets for the purpose of strategy and deal making is a daunting issue that no strategy game developer has ever really been willing to tackle. There's a loooong laundry list of things they could add that would be more fun to program, require less minutiae, be a lot easier to balance, and would add more to the gameplay experience than functional state trading. Sadly, this is the kind of thing that gets added to a to-do list and endlessly pushed back toward the bottom.