Death is unpredictable and nobody can guess it. Giving trust to one person in the family is a very right decision, because control of your account or wallet is not only held by one person but your trusted person will also have control. Creating a form or list of accounts and passwords and private keys is needed, it will become a cryptocurrency will. If we don't do this and our wallets cannot be accessed by anyone, accounts and wallets containing bitcoin or other altcoin assets will be buried along with death.
You are right, and as much as I know that in this life all you can buy is money, plus nothing and if that is the case there is no point in being selfish with the people who have always been around us, as long as you can help others it is something that will be rewarded, whether in this world or the next, everything helps, if a person dies and does not leave their private keys it will only contribute to making the economy even more deflationary, it is not bad, but the idea is that at the time of die your loved ones have something to hold on to, if money was not enjoyed in life, there is no reason to be selfish, that's what I think.