No one who knows what they’re talking about, but I’ve absolutely seen that argument advanced on multiple occasions, albeit usually with 30 rather than 24fps.
Before that, 30 was totally fine for the masses. In fact it was preferable. Cinema is the last big holdout and, apparently, it's going to take at least another decade before even mere 48 is standard. As someone who has been riding the 120+ fos for over two decades, going to the movies is awful, especially action scenes and panning.
I'm not sure what you're getting at with the 120 fps comment, because that is obviously not the frame rate of the finished product, so it's not the same conversation.
The 120 fps was regarding games. While movies are passive, they could still benefit immensely by doubling to 48. Not every scene in a movie is people talking and this is where 24 stops being adequate. Even YouTube has had support for 60 FPS videos for years.
I know it's not a win for the movie industry. They ought to hate it, especially the artsy types.
Don't know if cinema will ever drop 24fps. The shift to higher frame rates is of questionable benefit as it just makes movies look like TV shows. It seems 24fps is what makes a movie feel like a movie.