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?
Those are typically explicitly allowed through for various reasons. They want people to pay, but they also don’t want to stop Google/Bing and others from indexing it, and also archive sites. Which is why often people go through archive sites to bypass the paywalls, those can get a clean copy of the article and redistribute it.
It’s not a big problem enough that they’re probably deeming the loophole acceptable as most people still end up paying for it.