For example, the national bank of Bangladesh was compromised in 2016, believed to be a well-resourced attack by North Korea, and the attacker was able to attempt to transfer $1B. That’s about as severe as it gets, but the U.S. Federal Reserve blocked 85% of the transferred funds and of the remaining funds, all of the money sent to Sri Lanka was recovered, and they were able to recover some of the funds laundered through a corrupt bank in the Philippines whose manager was subsequently charged. About $64M was laundered through casinos which were not at the time required to follow KYC.

https://www.bbc.com/news/stories-57520169

So, not great, but the losses are under 10% of the amount the hackers had access to and there’s still a chance of recovering the rest - that’s survivable with insurance and it’s basically the traditional finance world at its worst in terms of corruption & poor preparation. Compare it to cryptocurrency, where losses on that scale happen multiple times a year rather than once a decade, and the attackers have a much easier time laundering funds through the infrastructure setup for exactly that purpose. North Korea is getting over a billion dollars a year from cryptocurrency, which is much better than the tens of millions at greater risk they got here.