Earlier quoted context omitted.
They know what they doing exactly. But they now have a reason to require age and ID checks to buy VPN. Then ban payments to VPNs that don't follow said regulation. You'll see.
You greatly overestimate our legislators. Of course, they may react in the way you described, but I sincerely doubt we're witnessing some great master plan.
Most parents don't want their kids looking at porn. While there are steps they can take to prevent it, they require some technical knowledge and are generally easy to get around. The easy availability of this content is what has changed. You used to have to go to a seedy bookstore, "adult" movie theatre, or video rental business to get it, and they wouldn't let kids in. Also you had to pay for it, and most kids don't have any money.