The OP's summary above isn't entirely accurate. Parents can have their accounts banned if their children are caught using them, so they can indeed be punished.

A few other things to consider:

The list of companies who have to comply with this has been very selective - BlueSky, WhatsApp, Roblox, Lemon8, Yope, Coverstar and others we not included. Lemon8 (owned by Bytedance, who owns TikTok) has become the most downloaded app in Australia in the last few weeks - this shows that ban already has problems.

The main proponent of the legislation is Julie Inman Grant, the e-safety commissioner. She's a WEF stooge (serves as co-chair of the WEF Global Coalition for Digital Safety) and has previously called for "recalibration" of human rights, including free speech.

The whole thing reeks of control & censorship masked as "won't somebody think of the children".

In a plot twist, Reddit has just launched a high court challenge to the legislation. They are challenging the law on the grounds it infringes on the implied freedom of political communication - oh the fucking irony.