For instance, so much of our early nuclear technology was dependent on the Shinkolobwe uranium mine in the DRC, and it's orders of magnitude better uranium purity than anything else we've found.
> Our best source, the Shinkolobwe mine, represented a freak occurrence in nature. It contained a tremendously rich lode of uranium pitchblende. Nothing like it has ever again been found. The ore already in the United States contained 65 percent U3O8, while the pitchblende aboveground in the Congo amounted to a thousand tons of 65 percent ore, and the waste piles of ore contained two thousand tons of 20 percent U3O8. To illustrate the uniqueness of Sengier's stockpile, after the war the MED and the AEC considered ore containing three-tenths of 1 percent as a good find. Without Sengier’s foresight in stockpiling ore in the United States and aboveground in Africa, we simply would not have had the amounts of uranium needed to justify building the large separation plants and the plutonium reactors [for the Manhattan Project].
~ Colonel Ken Nichols
Additionally, without the very dense energy in the easily accessible fossil fuels we've very nearly mined out, restarting an industrial revolution would be at best extremely problematic.
We've been OK so far with progress meaning we slam the door shut to independent replication of that progress in a lot of cases.