what are the benefits-risks of biographical fiction-memoir (in text or film/performance)?

In drawing and deviating from historical fact, what are the benefits and risks of biographical fiction and memoir (in text or film/performance)? What do we get from such works that traditional auto/biographies cannot similarly offer, or why do you think they have become so popular? With reference to at least two
different works , discuss specific advantages and disadvantages of these forms
for understanding our lives in the present. Do they expose or challenge questions of post-truth?