An encrypted digital backup (wallet.dat) can be replicated much more easily, avoiding the risk of storage failure. (But why not combine physical and digital backups?)
Descriptors were one of the best innovations I've seen in Bitcoin Core, after BIP32. It's a shame it's not very widespread.
Let's be honest, I don't think having 3 encrypted backups of my
wallet.dat will ever fail. In order for this to happen, all my backups need to be compromised (destroyed actually), at the same time, or at a small period of time in which I will fail to realize it and take precautions. It's extremely unlikely that 3 digital media will die at the same time and it's also unlikely that 3 locations will be compromised at the same time.