Investing all the money and assets into crypto isnt a good idea, just as you pointed out the fact of a person's death and the encrypted long string of codes he concealed will be in oblivion forever.

But what about the assets he made by investing in stock markets and the business initiative, maybe a ownership of a company or hotel resorts etc - the family member of the departed person will know about it and then possibly start to handover to other successor who are legally claimant of the properties.

Also risk is another factor to look at, adopting crypto 100% would be bad idea to bear risks and losing a great share as well.

But after all its about the personal choice to make for, "doing own research" is counseled.