Porn sites have been there almost 20 years. Why it is problem right now? Is there extensive recent research about it? Or now we just have the capability?
There's no reasonable demonstration of harm and a very strong correlation between availability of pornography and a big reduction in sex crimes. The purported harms are due to blocking reasonable sex education, leaving teens with the equivalent of Hollywood being the only model of sex they see. The original study that was created to show the harms concluded they couldn't find any to anyone, even minors.
Which makes sense- since exposing minors to pornography was a crime, and got even more illegal somewhere in that time frame, along with the web becoming "professional" (whitehouse top level domain mixup stories anyone?), the honest pornography sites all started self-regulating and asking if somebody is an adult before anything naughty gets shown.
Push from the different generation? Late boomers got very puritan with age, also see themselves as more moral, again with age.