> The future will bring technology to harvest more energy or otherwise neutralize the waste.
Optimistic. My turn: The future will bring technology to make spiders talk to cats. Prove me wrong!
> If there's some kind of apocalypse where science gets a hard reset, then sealed up nuclear waste is probably very low on the list of realistic and dangerous threats.
Nuclear waste might be relatively low in the immediate time frame after a science-resetting apocalypse, but the societies emerging afterwards will probably appreciate having a warning before they build their new settlements and water wells on a nuclear waste site. Especially if that nominally sealed site seeps out radioactive sludge due to critical containment failure only long after the settlement was established.