Money laundering used to have a fairly precise definition when the crime was first invented in the 1970's: "knowingly working to disguise the origins of money gained through crime". But over time various people (primarily aggressive tough-on-crime politicians) have watered down the definition until it's now more like "any financial transaction that someone somewhere doesn't like".
We can see the slide in the USA PATRIOT Act which removed the "knowingly" from the original definition. Now you can do money laundering without even being aware of it, under the American definition, simply by interacting with money that was earned by criminals.
Once they started chipping away at the mens rea requirement, the standards had to be redefined. Now it's not enough to avoid money you know to be criminal. You also have to avoid money you merely suspect might be criminal, lest it later on turn out to be the result of crime and you get sucked in after the fact. Hence banks turning away people who want to deposit cash. The fact that the cash has innocent origins is insufficient.
Then they went further and defined money laundering as failing to do 'enhanced due diligence' on any transactions related to a 'politically exposed person'. There is no clear definition of either term, meaning banks have to make it up as they go along. But the spirit of the law is that a PEP is anyone who might conceivably be corrupt. This was meant to fight corruption by forcing banks to investigate anyone who might be receiving bribes. With no definition and heavy penalties for non-compliance, which by this time is entirely in the eye of the beholder, private firms sprang up to compile blacklists of PEPs, some of which contain millions of people. There is of course no way to get yourself off such a blacklist.
Now throw sanctions compliance into the concept of money laundering and now you can be an evil corrupting money launderer simply by processing a payment from a firm in country A to a firm in country B where there are no laws in either country A or B against the trade, and the firm in country B is run by a guy who some powerful bureaucrat has decided is in some way shady. No evidence or trial is required and there's usually no way to get yourself off such sanctions lists. One US list of sanctioned people is simply a list of names with no other clarifying information, meaning people with generic names end up being treated as guilty-until-proven-innocent.
By the time we're done, you realise that every bank in the world is guilty of the modern definition of money laundering, simply by virtue of working with money.
If you're interested in the topic of abuse of AML laws, read the book "Treasuries War".