I support this greatly. But I think instead of debating whether this makes sense or not, or speculating, let's consider that it is already in effect and consider it an experiment. Let's see how Australia is doing in 10 or 15 years, will those kids be resentful or regret the ban when they're 30?

Extremes are bad on either end. unrestricted internet access, even to those who can't defend themselves against harmful content is an extreme, some balance is long due. Since most other western countries chose to risk their kids in the name of liberty, let's wait and see whose trade off works out for the best instead of speculating what will or won't happen.

I wish more countries would experiment like this, and even more countries would learn.

You can't argue for UBI or drug decriminalization because some country experimented and succeeded and then oppose this sort of stuff. In the US, states are supposed to experiment with laws like this, but they don't have enough power to regulate interstate communication or commerce.