It's distressing just how freaking similar the sales pitch is too.
What I'm loathed to even call the "real product": It’s time to stop flushing away valuable data.
The fake one: If I had information that could save your life or the life of your family members, would you flush that?
Just... wow
As it's most often seen on news sites - where scrolling too far gives you another article - a handful of reasons.
One: there are frequently still links (think "about us" / "contact us" kind of pages) in the footer that you might need to access, which you can invariably now never reach, because as soon as they're in view they're replaced by more content.
Two: as the parent poster so accurately put it, "fucking with the browser history". It becomes entirely indeterminate whether the back button now returns to the previous site, or just goes back by one piece of content.
Three: the new content is almost certainly unrelated to the page I started on, and not of any interest to me.