Life is unpredictable this is the more reasons why you need to plan ahead not because you are expecting to die or anything negative but anything can happen. Not revealing your seed phrase to anyone could actually be a form if securing it but at the same time it's not really a good idea because when something happens your entire Bitcoin you have saved up would end up being a waste. Being overly secure with your Bitcoin also has it's disadvantages and this is one of them.
If u Dey protect your seed phrase, u suppose know say anything fit happen to u any moment, and if anybody doesnt have access to ur seed phrase, then any amount of bitcoin wey u get don go be that. Just imagine say person die, and him get bitcoin but non of him family member sabi him seed phrase, that means say even if him family members Dey suffer after him death, and bitcoin Dey him wallet, nothing wey dem go fit do, na so dem go continue to Dey suffer.
If u Dey secure ur seed phrase, make sure say u keep am for place wey be say even if person die, e go get 1 family member wey go check that side wey u keep am and dem go see am, dem go fit use d money for anything wey dem want, or make u get one family member wey u really trust make u show am where u hide am, but na person wey u trust well u go show.