> Can they not manage to open a dollar-backed account somewhere?

If you want to do financial crimes and fraud, you can't (or at least, shouldn't) really do this.

Unspoken by the parent poster is that in practice these people are usually using crypto to break the law in some way, which is why it's valuable to them.

"Break the law" is too weak of a term since it includes routing around the monetary systems overseen by incompetent / corrupt / totalitarian governments.