Incentives matter. Why is the Euro banknote the most commonly forged currency? Because it’s easy to forge? No, because the consequences are much more lenient compared to forging US bank notes. You forge US banknotes and the secret service will surround you; for euros and the Europol may do something, but likely won’t. It’s like:
In America: “We got some fake bank notes? Surround!! Get some tanks..!! Some helicopters!! Some guys with machine guns! hurry!!” This why ppl (at least those with a brain) don’t counterfeit dollars.
In Britain “someone forged me some Euros… hmm… let me dial in the Central bank… What is their procedure for this infraction of most upmost importance? Fake bank notes? OK..let me dial in. We will have a resolution in a week, maybe a month. Fake Euros….hmmm….this a problem.” BY that point, the perpetrators will have gotten away. Incentives always matter. Make the cost of crime more expensive and crime will go down. People always lose track of this.