Was it? Are you just saying throwing manure, or do you think that children were regularly buying cigarettes in stores until just a decade ago?
Do you think that pornographers and social networks are desperate for child users, and that they provide a significant amount of income? Do you think that rooting everyone's computer so the sites can comply by flipping a switch and never have to hear about this again will bother them in the slightest, except for pornographers being afraid that adults afraid to lose their anonymity will stop visiting?
Social media has been trying to deanonymize users since Facebook's real name policy and G+. Deanonymized users are worth more. They love this idea, and don't give a shit about losing 17 year olds. It's proof that governments will do anything, even reinterpret their constitutions, in order to preserve the right of online multinationals to algorithmically manipulate adults for money.
Yes. Child porn was commercially sold in Europe and Japan until the late 2000s. There is no line that people won't cross for money.