Technically you don't need to tell anyone. You can put in place safeguards to where until your death occurs, no one will know shit. Now that could mean through an establishment of a trust, a will that you keep with your attorney/their firm..and of course will know of your passing and can then reach out to those listed in the estate and call them in for a sit down for a beneficiary disbursement of assets, you can use technology and established safe guards of these kinds to keep things very tight.
Both attorney/law firm can work together with the listed estate behind the family, then they access the coins and give excuse if someone have compromise it.
This is getting out of hand so the best choice is to hide as many assets as we can. I don't know about other cultures but here in my culture, the man of the house doesn't really share how much he values. He just asks the woman of the house what she needs and fulfills them never share them how much money he has and that's a golden rule in my opinion.
It's a wise decision I think.
Because if you reveal all of your incomes to your wife, if she know you bought something expensive for your hobby or entertainment, she will get mad. While there's nothing wrong for the men to enjoy a part of their incomes, they even give money for their wife for their own needs, not for house and kids, but the wife keep demand more and more.