On the main shard that I mainly play it's predominately the Governors that fund the stones. I would bet it's the same on most shards. Prior to the Blunder Beacons etc it required 40 trade runs a week, assuming you had maxed out at 5 items, to raise enough gold for 1 week of buff. I was lucky in that one of the Moonglow citizens, Leonidas, helped out greatly. He did thousands of trade runs. After the advent of blunder beacons the Governors hit those hard and most of us got the stones maxed out gold-wise so we would never have to do a freaking trade run again for the rest of our elderly lives. So what it costs the Governor was a lot of time and effort if they are not mega rich or they pay lots of gold every week if they were.
I'm not sure about today. There are those that understand the value of contributing their time and effort to their town. And then there are those that always expect something without any effort on their part. I believe that the use of the cargo to help fund the coffers was a great idea on the Dev's part and maybe it's time to make a change again. If you want to be a citizen you have to pay for services from that city. Something like once a week a certain amount of gold, that you've
selected from the menu on the stone when you first became a citizen, is withdrawn from your account and deposited into the coffers.
From what I'm seeing today is that players have no problem throwing gold at someone who will do the work they don't want to do. Throw some of that gold into the cities coffers and help out the Governors that have been working for the citizens.