hi kaw kings and queens the cities where you live as people build a lot of forge and no towers because that often just costs a lot of gold
Forges imply that they are making a product (i.e. forging something), which in turn brings in gold for my castle. Of course that's economically preferable to fortifying defenses, at least in a time largely governed by seeking out and fighting monsters (ebs), rather than a high risk of other kingdoms invading you (pvp).
Towers hamper growth for sure. They are helpful for war and PVP but the cost of them does hamper the gold plundered. However the Fails make up for it!