Money laundering does seem to be their choice in poisons.
Banks don't benefit from their customer laundering money just like landlords don't benefit from drug trafficking in their building: it's a hindrance and it costs a lot to do anything about it.
Source: I work on AML in a global bank.
By what metric? I’d argue the driving factor is their proximity to dirty money. Same with Russian banks. Then other people notice you’re used to looking the other way and you get word-of-mouth network effects. With money launderers.
They do, but it's nothing compared to what they make loaning money, which is their (and any banks) core business.