Actually I would hope other technologies would be discovered before the completion of the building, or else the entire purpose for the building would be moot. The thing is the engineers and architects designing and erecting this building would need to have some foresight in order to make room for and implement these technological advancements. Having a permanent structure could give any nation it was built in a significant advantage in the next space race both strategically and economically. Where other nations looking to launch vehicles and resupply them probably would opt to utilizing the building since building others might be considered prohibitive due to the enormous requirements for resources.
It is true the building could fall bringing a much more catastrophic incident, but with engineering, maintenance, and a planned life cycle that threat can be reduced. Simply put the building could be deconstructed when the engineers decide the time is right, and the resources can be recycled.
As far as elevating a space craft into space or launching it, it might not appear that a significant amount of energy is saved, but when you look at the energy being from a precious fuel source or from a renewable energy source such as green electricity the savings could be tremendous.
That was an interesting article.
