[ric2b]

Is it to stop downloaders? I doubt it since they work just fine, it's probably just a way to reduce resource usage on more constrained platforms like low end mobile phones or smart tvs.

There is probably a lot of code sharing among all platforms such that companies don't want to support two different buffering flows.

[chris_pie]

It also decreases bandwidth and processing server-side, when a user leaves before finishing the video.