But this has nothing to do with money laundering. If money gets into international banking system it's probably laundered already. Money laundering dosen't work

But this has nothing to do with money laundering. If money gets into international banking system it's probably laundered already. Money laundering dosen't work like you think it is - "shady offshore companies" is not enough to launder money because every one of this jurisdictions will work with law enforcement in case of money laundering. Then just follow the money and you will get busted. Shell companies will just make whole process longer for law enforcement agencies. Real estates in rich jurisdictions are used for stashing/anonymously investing money, not laundering money.