Have any crypto hackers even been found, let alone punished by the law?
A person following the letter of a smart contract for their benefit, while not breaking the terms of any legally binding contract they've signed, has yet to be charged with a crime (to my knowledge)
I haven't seen news of anyone from DarkSide being arrested for that hack yet though.
[1] https://www.justice.gov/opa/pr/department-justice-seizes-23-...
This is likely an issue of sophistication -- crypto hackers don't have decades of "best practices" knowledge to draw from, and may also feel a false sense of security.
Citation needed for such an extraordinary claim.
In the meantime, this article explains how and why that would be the case:
https://www.nytimes.com/2021/06/09/technology/bitcoin-untrac...
Basically the openness of the ledger allows law enforcement to skip some slow and difficult tracing and requesting of warrants.
On top of that, cybercriminals seem to make exploitable mistakes that have enabled stealing their private keys.