Criminals don't have to "recruit and pay huge numbers of naive bank customers"; in my jurisdiction, they just walk into a casino with a few hundred thousand dollars, exchange for chips, pretend to gamble for an hour, then exchange the chips for cash, and walk out with a nice receipt. There're more complex schemes involving real estate and other mediums too.
That’s cute, but it doesn’t really scale. Organised crime groups aren’t interested in laundering a few $100k at a go. They’re moving and laundering millions, you can’t put that through a casino without it being very obvious.
There is a huge international criminal industry that exists to find and hire money mules, and launder eye watering amounts of cash. Where I worked, we broadly assumed that the police weren’t interested in fraud or money laundering unless it was measured in 10s of millions. We reported everything, of course, but we only got call backs for really big schemes.
If you’re just committing fraud measured in $100ks, the odd of anyone bothering to investigate, and attempt to bring criminal charges, was basically zero.