Look, the reality is that kids will be kids ...
Remember the pre-internet days when the porn mags were on the top-shelf at the newsagent ?
I'm sure many of that generation will tell you stories of copies of Playboy being passed around in the school playground.
Or back in the VHS or DVD days .... someone in the playground would be passing around some porn.
Or, a UK-centric example would be the famous Page 3 of The Sun newspaper.... "giggle giggle...boobies...giggle"
Moving swiftly forward to the modern day. You can legislate about it all you like, but kids know their way around tech and will soon discover what you can do with a VPN or any of the other many workarounds.
I think the reality is more that the government is trying to legislate for things that could be resolved by good old-fashioned parenting and teaching.
Educating your child properly is better than doing the helicopter-parenting routine and trying to smother little Billy in cotton wool.