I think the difference is that a video-game is (as you said and viewed by me at least) as mostly consumptive rather than creative or constructive. I'm playing a game I know I'm dicking around and wasting time, the same as if I'm watching a movie or (even) reading a book for fun.
I'd say that some games are more constructive, like Minecraft or other games where you're building something or creating a story yourself... but I think what's being targeted is largely RNG lootbox online grind games. There's also an argument that top tier professional gaming isn't really that much different than being good at some other sport... and that's kind of an unfortunate side-effect.
The title is a bit misleading as there's no provision for 'offline' games.
Culturally for me... regulating media time seems like a parent's responsibility, and maybe this does give parents the tools to do that as the child could use their parent's account with their permission fairly easily.
I'd be against a similar thing where I live, but as I am not a Chinese citizen nor do I plan on living there, I can't say my opinion is worth much.
However, I think people are making this out to be much worse than it is as there's (for a long time) been a provision that children under a certain age can't sign up for online accounts (in the US) without a parent's explicit permission (with the implication that that the parent takes responsibility for monitoring the child's activity). This makes that implication more explicit as the child must use the parent's account most of the time.
This is one way of solving the 'online games have predatory practices against children / teens,' I don't think this is how I'd solve it, but again, not really my business.