> In 2010... the majority of video playback devices were already smartphones
I find this extremely difficult to believe. In 2010 the only widely used smartphone would have been the iPhone. The Motorola Droid was the first widely marketed Android device in the US and was only launched in late 2009.
The full context, to avoid confusion: "because no major browser supported it back then and the majority of video playback devices were already smartphones (without vp8 decoding capabilities)"
No major browsers didn't support VP8 back then, and among the remaining devices (other appliances than PCs with those Browsers) the majority of video playback devices were already smartphones (not supporting VP8 in 2010).
I find this extremely difficult to believe. In 2010 the only widely used smartphone would have been the iPhone. The Motorola Droid was the first widely marketed Android device in the US and was only launched in late 2009.