As a use case, how will grandma store her QarkCoins? Does she have to print private keys on paper, on a computer disconnected from the Internet, and with several separate copies that later must be put together? That's worse than even money under the mattress! Or does she need a hardware wallet, that needs to be backed up in case of hardware failure? In which case, we are back to square one again with private keys on paper or stored on a hard drive disconnected from the Internet. Extremely cumbersome management.
There is some wallet that uses a 12 word pass phrase or something like that, and then generates private keys with a deterministic algorithm. But would grandma try to remember the whole pass phrase or write it down on paper?
Grandma has a Hardware wallet - with multi sigs
but she won't call it that, she will call it my.
"Money widget thing" and she will know that if she presses this or that button she can spend money.
- as for long term storage, "Banks" revert back to the original "Coin storage" facilities they were in ancient times, literally they could be just protecting a crypto "Paper bond" with he ability to "make liquid" that bond and add to your "Money widget thing"
so in summary:
Hardware wallets, multi-signatures, and storage facilities. want to hear something terrifying?
just as the "Internet" equalized information flow , Crypto will "equalized" capital flows, if you haven't figured out what that means, i can say it like this:
its very likely that there will be a "re-balance of wealth".
I'll let you figure out the rest.