A common software wallet has a 24 word passphrase that you can use to restore it. It is just an app or a website that keeps stock for you. It works well enough. If you want to use a hardware stick, you can do the same, but be aware, these sticks can break too. You can forget passwords et cetera. And sure, without power the whole thing is gone until it comes back up. It is not going to get you through any crisis. It is fiat currency like any currency, but at least you are in full control. There is no government creating and spending trillions of the currency, making your savings worthless.

Precious metals will be valuable, but are they really when society breaks down? Imagine a long drawn out war would start. What are you going to eat? Gold and silver may be used to get things from people who have actual food available, but would it not be better to have this food in the first place? I think most of the value of gold is perceived value as it is "always going to have value". I for one have never desired to own gold, because nothing can be done with it that I care about realistically, except for the odd gramm of it on elctrical contacts. Gold does not go bad, which is a good thing, but that is exactly why it was used for backing up the value of money. I think a lot of it simply is psychology.