We expect it to not both support the laws that create a $100B black market for drugs in the first place, and then try to combat the consequences of its own actions and claim it's solving a problem, rather than creating two of them.
But there are other crimes that create illicit money: extortion/blackmail, human/child trafficking/exploitation, murder for hire, theft, ransomware/malware, and whatever new horrible ideas get created next.
Making money laundering harder makes criminal activity less beneficial to commit. And while ending the illegal drug trade will greatly reduce the need for anti-money laundering organizations, it certainly won't end the need entirely.