There is no universal way to store keys. Any of the methods is good only for solving their own problems. Keeping information about seeds-pharses in your mind also has a number of advantages and disadvantages.
This method is good because you have access to the "data" alone. So far there is no way around this other than using the "5$ wrench method". Also, the advantage will be quick access to keys due to the constant "carrying" with you and the ability to freely transport across any borders to anywhere in the world. The disadvantage may be that "memory" can bring surprises, in the form of loss of part of the information due to age-related changes or the influence of the "5th wrench" due to trauma, followed by loss of data. That is, this information carrier is very fragile and not reliable.
This method is good because you have access to the "data" alone. So far there is no way around this other than using the "5$ wrench method". Also, the advantage will be quick access to keys due to the constant "carrying" with you and the ability to freely transport across any borders to anywhere in the world. The disadvantage may be that "memory" can bring surprises, in the form of loss of part of the information due to age-related changes or the influence of the "5th wrench" due to trauma, followed by loss of data. That is, this information carrier is very fragile and not reliable.
Storing the "seed phrases" in your mind is not recommended, since there's the risk of losing access to your coins if you forget the seed. This is no different than a "brain wallet", if you ask me. If you really want to be safe, then you'll have no other option but to make several copies of your keys and store them in a discreet place. Redundancy and secrecy are the keys to preserving your crypto for the long term. If you do it right, your descendants will be able to access your Bitcoin without difficulties. There are many ways to store sensitive crypto information limited to your own imagination. As long as you follow the necessary security precautions, you'll have nothing to worry about. Just my thoughts
