The were very useful for modeling the structures they were used to model, and for educating on the flexibility of alternative geometries, as well as discussing

The were very useful for modeling the structures they were used to model, and for educating on the flexibility of alternative geometries, as well as discussing the veracity of existing assumptions. So no, they were never useless. The people who discovered them and studied them knew they weren't useless, which is why they were so willing to go down that road. They just didn't make anyone any money or solve any immediate broadly applicable problems in society.