Isn’t it the height of hubris to believe we could plan 100 years ahead? What cities haven’t radically changed in the last 100 years, with nearly everything being replaced with something better than they could have conceived of?
95% of European cities downtown?
https://en.wikipedia.org/wiki/Golden_Gate_Bridge#Conception
Buildings and roads are technologies that have existed for thousands of years, and may continue to exist for thousands of years. If you want to protect people and things from the world, it's hard to do better than walls and a roof. If you want to get from point A to point B by land, it's hard to do better than a network of cleared spaces. Sure, we may not know exactly what people in 100 years will want, but it's likely they'll still want buildings and roads.
I suspect monuments are the only thing that benefit from longevity.
I was imaginging government buildings built for 100 years, but I figure climate control and window design has radically changed and older buildings are probably uncomfortable in these ways without retrofitting.