Ad driven online content is especially bad for kids. But let's not pretend the only way to find an alternative is to end the world.
The fact is the "bad" solution is popular because consumers say they care about these things but then in real life they act like they don't. If no one watched the problem would solve itself. Thus, I'm not sure the solution is even to be found in platforms, if parents are burned out or don't have ways to make better choices for their kids.
That's a reason for these laws, to essentially just take it out of people's hands.
If all ads were like this we wouldn't hate them.
And I don't think they will start. It's good advertising for Ycombinator (I'd never heard of them before) and it doesn't cost a fortune to run really. They have one employee (or maybe 2 now?) and it all runs on one physical server. It's not a meta with a huge workforce and offices and datacenters all over the world.
What makes this impossible is the scale that people assume you need to cater for. When you limit your population to a reasonable size then moderation is easy and everyone gets to know the expectations of the community.
Unfortunately we have built a world in which people can live stream terrorist attacks or child rape.