If you share important details like the password of bank account and something happens, there is still a chance to get your money back. If someone steals money from your safe, you also might get it back but with Bitcoin, if someone steals it, there is a very low chance to get them back because there is no way to stop the Bitcoin transaction and if the thief doesn't tell you keys, no one will be able to get access to the wallet but this depends on the person.
Anyways, I'm against trusting someone when it comes to sensitive information like that. Yes, family members might be loyal to you to the death but you can't be 100% sure. There are many cases when things went wrong between family members. I think you can trust your mother and father more than wife or kids. I know many of you might tell me that this is the other way but today, men have less rights and wives don't care about divorce. Kids are kids and they aren't reliable.
But sharing important information with loved ones can be useful if you have an unexpected accident, they can access your assets on your behalf and use them if you pass away.
We need to remember that what we do and strive for is for our family, not just for ourselves. Therefore, they have the right to know our important information to promptly handle emergencies. Also, just because of money we doubt our loved ones and create distance between family members. Is it worth it when we always say we want the best for our loved ones?