However, criminals will always find ways to pursue their crimes so we can't blame crypto for it.
Criminals will find what to rely on as always. They are experts in technology usage. This is why you see them in every aspect of life. You are right too, they fall on bitcoin and rely on mixer to cover races despite the anonymity.
Definitely, even the fiats are been used for crimes, so, this particular case isn't peculiar with Bitcoin only but even with the fiats. As for today, criminals with good knowledge in Bitcoin are difficult to be track down by law enforcement agencies, this has given them more moral to always check into Bitcoin when they commit crime due to Bitcoin anonymity with mixers platform involvement.