There is no ad revenue
“In the (recent) past, you could attempt to make money online by going for scale – a high number of clicks – but that is becoming increasingly difficult. Even a very high-end website, like the New York Times, has online ad rates of about $8 CPM (cost per thousand impressions). Most newspapers and websites are much lower than that – and the number is falling every year.
Even very well read stories for large outlets may only generate $75 or $100 in revenue online. Not enough to pay a writer for a day’s work, let alone add in an editor, or any other costs associated with a large company producing content.”
https://theathletic.com/40690/2017/02/27/letter-from-the-editor-why-the-athletic-has-a-paywall/