The fabricators we used before The War were far more limited than the ones we have now. They could make spare parts while on extended deployments, but larger hull segments or structural members were simply too expensive and time consuming to fabricate. We built our ships the same way we had for centuries, one metal beam at a time assembled in construction yards by skilled men, women, or machines. Recycling the vast bulk of older ships was not economically feasible, and so we retired them to other duties. Boneyards. Reserve fleets. Cargo carriers. Ignoble ends for brave warships to suffer.