Honest question:

We are all the bitcoin multi-millionaires storing their coins? It seems like in an ideal world, you would use https://trezor.io and put that in a safety deposit box, or maybe use Coinbase Vault, but I am generally curious what is the current consensus on the safest ways to store these piles of digital money.

Generate a new seed phrase on a hardware wallet. Encrypt the seed phrase using https://github.com/FiloSottile/age and print out the encrypted seed. Store the paper in a safety deposit box. Keep the hardware wallet at home in a safe.

Write down the encryption key and the hardware PIN in an envelope to be opened in the event of your death.

All that said, this particular example is vulnerable in that you could be held at gunpoint and lose everything. So next we start talking about cold wallets vs hot wallets...