The fact that seems least likely to change is that most "paywalls" rely on Javascript, CSS or some other "feature" of so-called "modern" web browsers.
I have lost count of how many times an HN comment alleges "paywalled" in a thread and I am reading the article just like any other because I am not using a graphical web browser. I would not even know there was a "paywall". Paywalls have dependencies.