You can’t destroy keys, only hide them. Just like Satoshi’s keys, they become a bounty proving that the Bitcoin network can safely store your wealth.
Discussion
Well, let's just say let the data-medium that presently stores the keys stop persisting. I agree that all keys already exist in the mathematical sense, but I'm not trying to be abstract here. I'm being practical. Dumping all your capital into a volcano when you die is stupid.
You can make the utxo's unspendable. so if the keys are ever found, it wouldn’t matter..
https://bitcoin.stackexchange.com/questions/109747/how-does-op-return-burn-coins