If you care as much as bout the shrinkage of this game as you say, then I have a proposition for you.
For one or two ages (preferably two) take a time out from striving for the top and spend that time in the Ghettos/lesser kingdoms teaching them the fundamentals.
I suggest this because you all claim it is easy enough anyway. If it is so easy to trade, then take a break from your skd's and help the current player base to learn the fundamentals.
At the very least help them learn the fundamentals, because I promise you that you will be surprised at their lack of knowledge of even the basics.
Help them develop into a kingdom. Be patient, don't force hyperactivity.
If you do this, and they learn from you...we will have gone a long way in the process of restoring Utopia.
And trust me, you will find developing a kingdom out of average players a very challenging experience.
Do you think you can handle the challenge?