Pornography has historically been about as accessible as any other form of media. At first it was limited to hand-drawn on paper [1] (just like any other content before the printing press). Woodblock and later cooper-plate printing made it easier to mass produce (just like everything else). Photography was almost immediately used to produce pornography, as was motion picture film. And of course, the internet made it drastically easier to distribute digitally.
In short, pornography has always followed the existing means of media production and distribution.
There is an inherent rate-limiting in trading anything with others. Physical media gets lost/confiscated and you can only re-read the same magazine so many times before you get bored and move on.
Nobody invited you to an endless all-you-can-watch telethon of fresh content. That's where we are today.
It is not new, but it is plausible that through wide availability and deliberate exploitation of addictive behaviour ("Mindgeek"?) it has recently reached a state where it may tear society apart.
In short, pornography has always followed the existing means of media production and distribution.
1. https://en.wikipedia.org/wiki/Turin_Erotic_Papyrus