So once they start getting bored of the leisure time, their first reaction is to just keep doing it more to try and get the feeling back - which winds up feeling like work.
Which is pretty much exactly what my 2 year old does when he's tired: he doesn't know he's tired (or bored, or hungry) so he just tries to play harder to solve the problem for himself.
Some entertainment being necessary, I feel the vast majority of people do it too much.
Certainly but what I really wanted to highlight was passive entertainment versus non-passive entertainment where gaming has shown to potentially have cognitive benefits [0]. Though I highly doubt all games are equal when it comes to this and I'm sure some are even destructive in how they abuse people's reward systems.
Games like Turing Complete can even teach about how computers work from a transistor level.
[0] https://www.nih.gov/news-events/news-releases/video-gaming-m...
i've known binge watching cinophiles that have called in sick the next day occasionally , but I don't know of any that lost it all from the hobby.