system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are coffee cups in tv/movies so blatantly empty, rather than filled with weight?

In most shows I've seen, it's obvious that these coffee cup props are completely empty by the way they move, or by the sound they make when set on a surface. This wouldn't be that big of a deal, except for the brief disruption of immersion. 

  
   
In my attempts to search for previous ELI5 questions about this, it's obvious that filling opaque coffee cups with liquid isn't a good idea because of potential spills, as well as the amount of liquid an actor would have to ingest throughout all the takes required.....but my question here is different: Why not just simply fill them with a solid weight, like a gelatin with a similar density as water, to more realistically mimic the way these objects should move?
gpt
And the million dollar question you have to answer: does that add anything to the storyline of the film for the avg filmgoer?   No.

Just like movies never say goodbye when hanging up the phone, never lock the door, cock the gun even on a gun that doesn't cock, hacking by typing furiously at the keyboard, looking at a screen so bright the reflection off the glasses is blinding,  10 bad guys fighting the hero will take turns attacking, bad guys have absolutely no aim when shooting,  bad guy has to explain the entire evil plan for 5minutes before attempting and failing to kill the good guy.