Honestly, the expectation that a 2012 computer will play 4K video seems a little unreasonable, no? 4K video virtually didn't even exist back then. I'm actually amazed it even handles it in h.264.

This isn't about saving companies a few cents on bandwidth. It's about halving internet traffic, about doubling the number of videos you can store on your phone. That's pretty huge. You can still get h.264 video in 1080p on YouTube so your computer is still meeting the expectations it was manufactured for.