There is no solution yet.

From a bird's-eye perspective, 3 things are needed: Create a key, derive an address from the key, store the key.

Creating a key safely is possible with dice. You would probably create a seed phrase instead of a key directly, but for this discussion it is the same.

Deriving an address from the key is hard and I have not yet seen a good protocol on how to do it. I have read through a bunch of descriptions of how people do it and they are all weak and brittle. The most popular seems to be "I order a hardware wallet and follow the instructions that come with it". But even people who put a lot of thought into it come up with weak and brittle approaches. I would think there is a way to do it safely. But I have never seen a description of one yet. It might involve multiple computers, multiple software implementations and a hell of a lot of work to create a multisig that is not prone to a single attack vector.

Storing the key is probably the hardest. The most popular way seems to be to store it in a drawer or a safe. So now those coins are just as safe as a piece of gold would be. Or they use a multisig and store the keys in multiple locations. Quite painful. As you have the ongoing problem of keeping those locations accessible and safe at the same time.