During early negotiations for Avengers: Age of Ultron, Disney threatened to recast Chris Evans and Chris Hemsworth after they demanded fair pay matching the first film's success.
Robert Downey Jr. walked into the executive suite, sat down, and threatened to permanently quit the MCU on the spot if his co-stars weren't given their asking price. He didn't take a single dollar extra for himself that contract-and he told Evans and Hemsworth to thank their agents, never taking credit.