What does ranking vs. chronological having to do with infinite scrolling?

You can have a ranked paginated UI. You can also have an "infinite" (until you run out of items, but this is not different for ranked) chronological UI.

Moving away from chronological allows them to feed you more addicting content, as does the infinite feed. They involved together because they work together synergistically.

It’s of no value to point out both can technically be implemented independently. That isn’t what happened, and even if it did it would still be user hostile.