Almost all films and tv-series that tell the viewers, that they are based on true events or real/historical characters, are predominantly fabrications of the screenwriters
There are basically two sub-threads to the above:
- filling in the blanks, because the screenwriter does not know what happened between - as an example, two real life characters having a conversation between them alone.
- replacing factual events, quotes etc with your own, effectively rewriting historical facts. Perhaps to create drama, character development or compress a timeline for narrative reasons.
My most despised example of both, is the hit film Bohemian Rhapsody, which distorts and falsifies so many details about Queen's origins, the making of their songs, their tours and especially Freddie Mercury's personal life. It is especially monstrous, because Brian May and Roger Taylor approved the script, fully aware that the portrayal it paints of Freddie Mercury, their friend, is mostly a pr fabrication and simply not true. John Deacon had no involvement with the film whatsoever.
Filling in the blanks is to some degree acceptable and necessary, its the wholesale invention done on the assumption that the average person won't notice that annoys me.