Just to expand on this, Enter The Dragon was arguably itself derivative of the Sax Rohmer stories especially Braithwaite, the British Intelligence agent (aka Nayland-Smith), and Han (aka Fu Manchu), the criminal warlord cooking up Opium in his dungeon.
The original Fu Manchu series was obviously derivative of Sherlock Holmes, with Smith standing in for Holmes, Petrie standing in for Watson, and Fu Manchu standing in for Moriarty. The series was arguably racist against the Chinese, but this needs context.
The British had done their usual in the 1800's attempting to gain a foothold in China. They funded opium production and used it to trade for tea and spices, both for profit and to destabilize Chinese society and undermine the Qing government. It needs to be kept in mind that there WAS a Chinese underworld, hence the idea of Fu Manchu as a mastermind behind it.
Rohmer was a journalist covering London's Chinatown in the 1800's and his stories were inspired by what he'd seen, so somewhat drawing on fact.. One-sided negative facts, and part of the propaganda we have seen time and time again for generations, and I'm sure we will see more of in the future.
The switch from Fu Manchu to the Mandarin is due to Marvel losing its license to Sax Rohmer's characters. From the comics I read in the 70's I'll miss Nayland-Smith and Black Jack Tar, but I think it's a fair adaptation that lets them move forward.
Note: I haven't seen the movie yet, I'm waiting for a night my son and I are both free.