But if this piece of paper gets lost, burned, or stolen, who will then cover the enormous losses?
I don't think Coinbase can cover a 1 million Bitcoin loss. They again, maybe they are better at secure storage than governments now

For example, the South Korean tax authority stores cryptocurrency
this way,publishing a photo of the ledger with the seed phrase.
I can't figure out from Google translate if this was very dumb, or just trolling by sharing the seed phrase to worthless tokens.
There was a funny story in South Korea.
The tax authorities published photos of the seized wallets and seed phrases, but
the wallet contained PRTG tokens, which had a 24h volume of several hundred dollars.
The blockchain explorer shows the tokens price at almost 5 million, but it's practically impossible to sell.
https://www.coingecko.com/en/coins/pre-retogeum___
Government officials don't know how to handle digital currency, but the crypto exchange has vast experience.