That doesn’t apply to fission power due to breeder reactors. We can wring more power and efficiency out of nuclear waste by just sticking it into a breeder reac

That doesn’t apply to fission power due to breeder reactors. We can wring more power and efficiency out of nuclear waste by just sticking it into a breeder reactor to absorb neutrons until the waste is up-converted back into fuel. That’s where the increased efficiency and gains will come from in the future - better and better ways to convert big atoms into fissile atoms. It doesn’t matter if those big atoms come from nuclear waste or some other source (like thorium!)