I don't know how transparent and genuine other countries governments and their financial regulatory authorities has been with their citizens and the masses entirely, but speaking from experience, my late uncle who died during the the COVID-19 and left over $1,700 for the family in his bank account and after much processes the wife being the next of kin and the family as a whole has been unable to have access to the account and that is just how the money died off and only the government knows the fate of the fund til today.
In my country Nigeria, the government and the financial regulatory authorities has always kept hidden facts from us which would had been an added advantage to our knowledges and even contributes to precaution measures that we could avoid common mistakes that may seem insoluble or a long time to get solutions to it.
I recently came across this
https://youtu.be/s07NUfpPzSM?si=SY8wpCVbjgNHn2zy youTube video which a formal banker from Nigeria discloses about what the bank does not want us to know via how a next of kin would not be accessible to the benefitials bank account that if paraventurely the bank account holder dies, the bank will deny access from the next of Kin to the account if the next of kin is not an automatic signatory to the account or the account holder has not made a written will to determine the legitimacy of the next of kin.
So the bank would go a legal probate process to decide who gets the money.
Meanwhile... This legal probate in my country can take a very long time maybe years ahead to verify the processes which is definitely uneasy to meet up those tasks.
Even after the whole processes is being overcome, the next of kin would be demanded to pay huge sum of money for a legal fees to be able to have access to the account but meanwhile, the next of kin has been mentioned with all necessary requirements being provided during when the benefitial was on the bank account opening processes but the bank could not make the terms and conditions obviously for the account owner to take early awareness of it.
So this is assumed to be why the government and the financial regulatory authorities in my country has been fighting over cryptocurrencies facilitating crypto trading with the naira (#) on the Centralized P2P Exchanges.
The interest of the government is to control the centralized exchange with the forebeing of syphoning our Crypto funds.
Literally they also want to make away with our Crypto assets when we are gone and clearly stated and obvious, there is no next of kin attached to our Crypto Investments.
So, the government would want to also do away with them as they rebels us with the Centralized Fiats.
You can imagine how selfishly logical the governments can be? They tends not to let us know what is crucial and necessary but just concerned about how they can rebel the us.
For the issue of next of kin for any account holder in Nigerian Banks that I know, I know for sure that at the point of opening an account for every individual, there is a column for next of kin which is to be written down by the original account holder, so that should incase of any eventuality in the future, the next of kin will step in to request to be in charge of the account or withdraw the funds in the account. however this process is followed after there is an authentication and some level of proof from the next of king that he or she is actually the next of kin, most times they are legal documents signed from both sides which is the bank and the next of king. for me I've seen that it has always been an easy process except for this particular case you're talking about.
As for the cryptocurrency market and the Nigerian government, I see that they've recently termed the crypto sector as informal sector that they cannot control the financial activity hence they want to use one sanction or the other to cripple the activities of cryptocurrency, forgetting that the whole idea of cryptocurrency is to decentralize it, so that government cannot control it. so this reality is what Nigerian government don't want to accept, hence the back and fought issues with crypto.