There's an apt outcome of the analogy too. It's likely the grapejuice is better for you before fermenting it, oh and the grapes themselves are better for you than removing all the fiber and the physical bulk that can help satiety.
I feel the same way about games. They may have positive effects over a null control (like sitting and staring at the paint on the wall), but reading a physical book is probably better for reading skills than an RPG.
Flow state increases retention and positive benefit, and flow state is often a function of motivation (fun), and more importantly, level of challenge. The benefit games have over nearly every other medium of experiencing a concept, is that the level of challenge is highly personalized.
If you spend a lot of time in one area of an RPG trying to comprehend the plot and thus solve the puzzle, it's still fun because you are moving around and performing more interactions and gathering small bits of context. Compare that to if you are stuck trying to comprehend one page of a difficult book as a 7-year-old.
Playing games allows our brains to catch up to complex concepts through (simulated) movement much the same way as going on walks allows us to process a difficult problem or complex system that is on our mind.
Also worth adding to this thread that motivation is a feedback loop mechanism. If you're super stimulated by these slot machine like games, you're not going to find the long rewards of completing a book a week/month a very "motivating" option. So it's also worth looking at the motivational damage these things do to a person and how it's eliminating the motivational possibility of doing something of higher value. Cue the "dopamine detox" part of the internet.
> is that the level of challenge is highly personalized.
I agree and this is a good observation, which maybe can be had IRL, but i agree that it can be easier implemented and more granular in the digital realm.