Suppose you didn’t bury it and just stacked up heaps of those nuclear flask thingies and wrote on them “waste we didn’t know what to do with”.

Suppose this went on for several hundred years until a better solution was found, and by that time there was many thousands of those flasks.

I bet our descendents would be glad that we had left them with those rather than continuing to pump waste we didn’t know what to do with into the atmosphere.