The missing phrase in the post is "hardware acceleration", which is is completely broken for VP8/9(In Firefox & Chrome, IE&Safari doesn't support either).
I'm using an extension[0] to force youtube to serve me with h264 in order to be able to watch 4K videos & maintain reasonable battery life.
I'm using an extension[0] to force youtube to serve me with h264 in order to be able to watch 4K videos & maintain reasonable battery life.
[0] https://github.com/erkserkserks/h264ify