[ac29]

You're right, it is more complicated than I assumed. I use Chrome/Linux where nearly 100% of videos are served VP9. According to this [0] 61-69% of browsers support VP9, but I cant find a good source as to what percentage of youtube is actually served with VP9.

However, in the last year 25,000,000,000 hours of VP9 video have been served on youtube [1]. Maybe this is a minority of web video, but its hardly dead.

[0] http://caniuse.com/#search=vp9

[1] http://youtube-eng.blogspot.com/2015/04/vp9-faster-better-bu...