Not a 100% certainty but for smart contracts going through an audit like with Certik can really help avoid these issues.
How did we move from horse to car? Over many years. Same with fiat vs. BTC. It will for sure get ugly at some point, but having the life raft in the water as your ship is sinking will at least allow anyone to jump off and swim to it. The obvious thing is that debt cannot keep growing faster than incomes and GDP, and yet that is the only way to keep this going. This cannot be fixed via the traditional routes.
Never happened, we're just going through a multi-generational dip on buggies due to the motorized vehicle fad. Buy the dip! If you don't dive in now, you'll be sorry when the horse & whips rally.