And those places, do, in fact have processes regarding deceased and/or power of attorney. [0] This is not something that has sprung up out of nowhere. People die, everyday, which means that these companies have to deal with that fallout, today, not at some strange point out in the distant future.
My point is it's happened to a miniscule number of people compared to the (roughly) steady state we'll eventually reach when it's not just the relatively 'techie' older generations & newer ones dying 'before their time'. 'People', as opposed to the companies that you say deal with the fallout everyday, will be a lot more aware of the scenarios and problems it might cause, and what they can or cannot do to ease it.
[0] https://support.google.com/accounts/troubleshooter/6357590?h...