The IT solution for such succession issues is something most people do not want, especially the giants living on walled gardens. The first part is be LOCAL FIR

The IT solution for such succession issues is something most people do not want, especially the giants living on walled gardens. The first part is be LOCAL FIRST for anything, living the FDE key available in a safe, secondly having digital IDs, the PGP/GNUPG model, where anyone have a pair of keys, the public formally recognized by the State, and allowing third parties to accept the heir + notary as valid means to transfer an account properly. Aside all home systems must be IaC style, so anyone can manage them reading a single config repository NOT needing to know the current state of things outside the repo. The main issue though is that anyone use computers, but only very few know them, as a result most of the population is digitally illiterate to a point of being unable to do all basic stuff they need to do.