Why do people let tweens wander a mall unattended when there are things like brewery/restaurants inside? Because it's illegal to serve them alcohol and as a social convention you know they won't.

Society works a lot better when we make the few bad actors that are out to exploit children stop, and instead expect everyone to look out for them/generally behave in prosocial ways. Things stop working when we say "why wouldn't you assume everyone around you is out to harm your kids and act accordingly?"

We can just say "actually you're not allowed to put gambling in a game targeting 7 year olds".