Most major news sites, as well as some other sites of reading content like Medium, have a paywall for certain articles, but those are easily defeated by people who bother to search the internet.
As I suspect said companies are aware of that, and they don’t react to properly protect their paid stuff, what do they expect to gain?
Cost vs reward.
Is is worth spending several thousands of dollars to develop systems to block access. How many wil actually sign up?
The irony is that said systems that successfully block access are how many websites worked as far back as the late 90s, with “member exclusive” areas.