Actually it is WAY easier to use paper money for crime than cryptocurrencies.

Aha! How would you know?!

Kidding aside, I have zero clue what the actual adoption rate is for Monero in the seedy underworld of common criminality, so I can't really challenge anyone on this argument.

I can say if I were a criminal, I'd want to keep it as low tech as possible. Given how sophisticated computer forensics is, I don't think I'd be able to keep everything "clean", digitally speaking.

It depends on the kind of crime. Some crime is easier with cash.

For example, many professional bartenders commit tax fraud every day by not reporting cash tips. This is directly facilitated by paper currencies.

It is not "facilitated" by it, that is just because cash tips are given in paper currencies and not in Monero.

If tips were given in Monero, the tax fraud would be even easier.

Uh, why would it be easier?