~snip
Fact actually is I wouldn't like to put too much of a blame on mixers because everything that has a good side has a bad one too so you should definitely expect hackers and scammers to exploit the bad side too just like good enthusiasts will exploit the good side which is simply maintaining privacy.
The mixer part is just a speculation. They could as well make use of decentralised platforms to make the funds untraceable. Mixers have been doing a great job in improving privacy for bitcoin users for long. There's definitely going to be a bad side. The government knows that cases like these would be inevitable in the future so they try every possible best to eradicate them. Aside privacy, some people use mixers for illicit activities. Even the government that may claim to be against it, no one is truly innocent. They act like that in public but may go dirty in the dark. This bybit case was unexpected and I guess their security team should try their best to improve on that.