The Batman: 9 Things That Are Impossible If Ben Affleck Returns
9. A Death In The Family
Thanks to that so far undeveloped sub-plot in Batman v Superman establishing that the Joker and Harley Quinn killed Jason Todd, we know for certain that we're already beyond the point in the timeline where that story can be told. It has been co-opted as the reason for Batman's more brutal approach to crime-fighting, so it sort of served a purpose, but it's another example of a seminal canonical moment being used as superficial furnishments.
Sure, we might yet get a Red Hood story, since all of the framework is there, but that's only half of the story, and it's one that absolutely deserves to be told as two separate movies (or even a trilogy) rather than one split between present day action and flash-backs.
If nothing else, seeing Batman lose his protege after building up a relationship with him would be the kind of emotionally true moments that good film-making should be framed around. Knowing Robin is already dead just doesn't ring as true.