Hundreds of billions of dollars are staked on the security of Bitcoin protocol. Bitcoin is not some hyper-complex enterprise software suite with thousands of hidden micro-bugs just waiting to be noticed and exploited. It is lightweight, straight-forward and provable by mathematics while being the single most financially exposed and the most audited piece of code ever.

Don't you think somebody would notice something by now?

Anyways. Do you really think the network wouldn't do anything about it? Even quantum-proofing Bitcoin is a possibility, so why not fixing a bug?

I bet that the humans running the machines that run the Bitcoin network would simply update their Bitcoin-core and go on from the point just before the transaction that stole everyone's Bitcoin. A significant nuisance, but hardly a catastrophe.

I never said that. I said Bitcoin won't go down to $0. Bugs have and will be found and squashed.