Education on an ongoing project is far easier then rebuilding fresh, even with better science and engineering. We often see this in infrastructure, like train

Education on an ongoing project is far easier then rebuilding fresh, even with better science and engineering. We often see this in infrastructure, like train electrification, tunnel boring and so on. Trams is a good one, so many cities got ride of their tram system, 50 years later they want to build it again and many of them issues.