The storage device doesn't matter - it's the seed words that generate the wallet that matter. If you memorize them you're good (short of someone beating it out of you or legally compelling you - even then they'd have to be able to prove it existed in the first place).

You can trivially prove your gold ingot exists because you can just find it. It's also way harder to move your gold ingot out of your war-torn country, harder to transact with it, etc. The storage device does not hold the actual coins, just a private key that lets you update the public ledger that determines ownership (thinking the storage device holds the coins is a common misunderstanding).

I'm an open-minded skeptic, but there are real technology advantages to blockchain and cryptocurrency, there are a lot of scams too for sure - but that's not the interesting part. The HN median opinion on this is wrong as it often is (it was wrong about EVs and Tesla too).