Yeah I feel like we need some parameters around why gold is "durable".

Firstly, gold is physically soft. Sure, it can't be atomically destroyed, but who wants a puddle of molten gold or gold vapor? Also, you can't back up your gold, and I feel like redundancy should be taken into consideration for durability.

Secondly, keys can be made just as durable as gold and even more, depending what you stamp your keys into. Keys can be backed up, geographically distributed, etc...