What happens to your Bitcoin after you die?

Have been and avid bitcoiner and stacker for the past 18 months or so. I have my stack on a cold wallet. In case of my death, my wife knows how to find the wallet.

But what if we both die? What if one does not trust their spouse to know where their BTC is anyway for that matter? How do you leave your BTC wealth to your kids/family in your untimely death? How to pass along seed or keys without them being compromised? I've been thinking about using a safety deposit box, but then again I'm relying on a brick & mortar bank. Further, how secure are are safety deposit boxes anyway? Seems like there should be a better solution. A major downside to "not your keys, not your coins" is that anyone who comes across your seed can take your coins.

Trezor has an option where you split your seed phrase into three separate parts and 2 parts are needed to access wallet. One idea I had was to utilize this method, and place single portion of seed into three separate safety deposit boxes at three separate banks. And in the event of my death, leave my children as beneficiary. This seems reliable and safe, but costly.

What happens to your Bitcoin after you die?

One benefit of fiat and centralized currency (in the US at least): in your death, your assets are passed reliably to those whom you designate.