"Of course we want to honor his memory. Shove a stick in his ass and call some puppeteers."
Before making Enter the Dragon, Lee had been working on his own movie, The Game of Death, but had only managed to finish filming part of the climatic action scene. The sequence featured him fighting the likes of Kareem Abdul-Jabbar while encased in a yellow track suit that proved his skills at martial arts did not extend to costume design.
The director of Enter the Dragon took these unfinished scraps and tried to cobble together a finished film using new footage featuring several stand-ins who, aside from also being Asian guys who knew how to kick and punch, didn't resemble Bruce Lee in any way.
To explain this, the producers inserted footage of Bruce Lee's real-life funeral to suggest that the main character had faked his own death, thus allowing Bruce Lee's fill-ins to spend the rest of the movie wearing fake beards and other wacky disguises without disrupting the narrative. We don't like to judge, but when you're including shots of your star's actual dead body lying in his actual casket, anything less than the biggest box office receipts of all time would land you the worst haunting in the history of the universe.