Presumably because it's funny, whimsical, and imaginative.
Someone say that this is pointless since you can do the same thing by utilizing existing tools like your table!
I really wish cars had more modular docking systems for electronics, drinks, snacks and sunglasses.
What you're looking for is a "cup holder expander" or "cup holder adapter". Much like the cigarette lighter became a power delivery standard because it's there, so too has the cup holder become a standard, although admittedly quite a bit more nascent.
https://www.ford.com/support/how-tos/owner-resources/vehicle...
https://www.thedrive.com/news/44276/ford-releases-blueprint-...
Turns out caffeine was all that was in the way of AGI.