Earlier quoted context omitted.
Let's say I have a 3-of-5 multisig. That means there are 5 hardware wallets. I put a hardware wallet in my safe in my house, one in a bank deposit box, and 3 with 3 friends or relatives. Now a thief needs to steal 3 of these to steal the coins. That's going to be hard for a thief to do. If a fire or natural disaster happens, it needs to destroy 3 wallets before I lose my money.
Yes, it's a low risk. Perfectly executed this is maybe a risk of one in ten million. So on a worldwide scale this means that it would happen every day, to someone. But it won't be perfectly executed. Let's say you need to do a transaction while you're moving house. And maybe one of your relatives is in financial trouble. You (probably) don't have the means to do what banks do, and hire an armored transport.
Further, unlike an armored truck full of cash, security by obscurity is really easy here. That and for a short duration (say moving houses as you suggest) one could wipe a cold wallet clean and just remember a seed phrase. Personally, I don't have enough wealth to make this sort of maneuver at all worth it, but it's completely do-able.