The point is to make children used to checks.

It's a didactic law.

IRL usually children grow up feeling they are free (except for their parents) to an extent.

This is intended so that identifying yourself in the Internet were normal by the time you grow up for it to matter.

But, of course, there might be some good considerations, if you're into playing devil's advocate. People might remember which stupid shit they were posting when they were younger, and want for future generations to be always conscious of the difference between pseudonymity and anonymity, and superficial anonymity vs real. People might want to make it so that nobody had a false sense of security, leading to really bad mistakes. People might want this to be the step preceding some way to fight bots.

And they might even not have good considerations, but eventually realize that the oppressive system they are building is best rebuilt for something better and used differently. Wouldn't be the first time in history.

It's just that laying down your arms in hopes for that is unwise.

This falls on the parents instead because of dumb laws every one has to deal with this, I just hope that not all countries are this insane:

users in the UK have had to take photos of themselves and upload it to a service that uses AI to guess their age. Or, send in photos of ID such as passports or driving licenses.