90s dialup Internet was not in every house yet. Microsoft succeeded in getting PCs in homes but free was not the name of the game with pay per minute online access. Things didn’t really take off until the 00s with broadband access.
Not true. Pay per minute Internet access did not last that long, by the mid 90s it wasn't even a thing. Image porn on the Internet was a big deal in the 90s, especially in the second half of the decade. Plenty of people had dial up, hence the massive popularity of ICQ and later AIM. And of course email, online gaming, and the dotcom bubble...
And I never said Internet porn. While not free, porn was still cheap and easy to get on cable or satellite, or at video rental stores.
I doubt it was just porn though. I believe that simply getting teenagers / young adults inside for long periods of time (and not just for the purpose of abusing drugs / alcohol) is a big victory (for crime stats, not society in general).