Passkeys are also fine imho, I use Apple Passwords and share passkeys with various groups (partner, immediate family, extended family) for various systems, depending on access audience.
Also, consider a legacy contact if you're in the Apple ecosystem. For those who rely on me as an unofficial trustee and guardian, I have them add me as their legacy contact, and I then print out multiple copies of the legacy contact key page, laminate it, and distribute it physically (it's a one page QR code with some details on it). It can also be bound between Apple accounts. A death certificate will be required to access a legacy contact.
https://support.apple.com/en-us/102631
https://support.apple.com/en-us/103128