Is the problem solvable? Of course it is... Just use the provided wallet software, use a password to encrypt your wallet, and back up the seed phrase, or backup the actual wallet file.

It is literally already solved.

EDIT:

Proposal:

buy 6 different 8gb flash drives for $40 or less, backup the encrypted wallet on each of them, with a printed piece of paper with the wallet. Buy a $50 fireproof lockbox and keep the key with your regular car/apt keys. Boom, redundancy. All for less than a hundred bucks.

It should be possible to have similar UX/Support to traditional banking while having users custody their coins. Multi-sigs and digital identity would be very useful in this regard. Trusted 'recovery' parties or hosted services that intentionally limit risky transaction behavior. For example, you could have a scheme where funds in a smart contract are gated by a personal signature allowing one to spend up to $7500 in a 24 hour period, but requires secondary approval provided by a trusted company to send more (on top of your signature). If you need to break the limit there could be a verification requirement from the company or emergency override key you keep safe. Crypto will be most successful when people do not even know they are using it. Assuming no legal issues with adoption, there are more challenging taxation and liquidity considerations to using fixed supply currencies at scale than usability for the average non-technical user

P.S. Software and Hardware wallets are little different but you can loose either in many different ways..