> that old computer or phone that has had a factory wipe
Don't trust old phones with too much value.
There are hardware bugs on Bluetooth, WiFi, and SS7 that are fairly easy to hack with the right setup and SS7 especially is built into the same baseband controller so main memory can be exfiltrated over cellular even without an active SIM.
Keeping it turned off most of the time reduces the attack surface, of course.
A few phones do better - switchable modems, etc. but very few and even some phones that meet GrapheneOS specs are imperfect.
An old ThinkPad with LibreBoot is probably OK if you want to get really nerdy. Yet 0.00001% of the population can handle that.
Hot/warm/cold is of course another layer of protection. But again, very few people can manage this.
Still, if you are transferring $200 to your dedicated phone to go out shopping, it's not very tragic if it gets lost.
We really don't have a good solution for the 99% yet. So companies like Binance step in and make a profit (as long as they can assume liability and responsibility for losses).
It sounds like that devops laptop had /way/ too much access. Where's their multisig for billions of dollars? I would never have guessed Binance would be one so lax. Doing it right is way cheaper than a shareholder lawsuit.