It is estimated that around $400 billion is spent per year on illegal drugs* alone, never mind weapons, credit cards, pornography, fake documents, and all the other things you can buy on the dark web. As long as fiat is widespread, cold hard cash will always be the most anonymous method.
The funny (or sad) part is that most of what criminals use Bitcoin for is put against the all time high so that it looks worse than it actually is. This is a form of statistical manipulation that is not uncommon for news outlets.
Nothing in the world will ever come close to the illegal activities that are financed with fiat. News outlets can twist numbers in whatever way they want, it's futile to even remotely come close to fiat in that field.
I'm glad that nobody really cares about this anymore. Back in the days it might have shocked people, but that's no longer the case. I see more people actually counter these articles by pointing out how bad fiat is when it comes to criminal use.