It does change everything, when people fear nuclear waste, they talk about literally eternal. Otherwise we could say that reforestation is not possible, because it takes 70 years (if you are not just growing wood for fuel, furniture and mulch, but restoring a system).

If it's not literally eternal, then it's a working cycle which can be used and be more efficient.

EDIT: I've realized that the thing I'm remembering was written about fast-neutron reactors, which most are not, so you are right usually. It's actually funny that Russia makes more ecologically clean reactors than USA. Stupid, but funny.