This question already has an answer here:
Some non-paywalled news websites started recently adding 'see more' dividers to their articles on mobile versions of their sites.
This made sense on sites likes the Wall Street Journal, where you have to be a paying subscriber to continue reading, but what about free-to-access articles? What's the purpose of adding them there?
We can't say that it's for analytics (how many people read beyond this threshold) since we already have more precise tech for this that doesn't require the user to click on a button.
Some notable examples are: qz.com, techcrunch.com and nytimes.com.