Other hobbies build transferable skills, abilities, knowledge or muscles. A very small number of video games can do some of these, but it isn't the norm.
No, no, I'm crazy. Because some have kissing, we should ban TV and movies. They're a waste of time (because it doesn't promote me as a source of labor) and are a gateway to video pornography - the horror!
I'll go with a popular one with this crowd: chess. What "skills, abilities, knowledge or muscles" does playing chess improve other than things directly related to playing chess? I can think of game theory but that also seems like it could be improved by playing other games. I think you'd agree that chess is a game and a waste of time but you'd probably not agree that it's bad that it's a waste of time; wasting time is rather the point. Time flies when you're having fun, as it goes.
Saying "its a hobby like any hobby" glosses over the obvious fact that not all hobbies are made equal.
I didn't write that. I wrote it's "only a waste of time as much as any hobby" because the person I replied to wrote that they don't want to recommend video games as a hobby to children due in part to it being a waste of time. It's moot that the hobby is a waste of time because the point of it is to be a waste of time. They might not want to recommend games as a hobby to children for similar reasons as to what you detailed but that's different from not wanting to recommend the hobby because it's a waste of time.