Computers wouldn't have been fast enough. Moore's law is a hell of a drug. In the mid '90s, PCs often weren't fast enough to decode DVDs, which were typically

Computers wouldn't have been fast enough. Moore's law is a hell of a drug. In the mid '90s, PCs often weren't fast enough to decode DVDs, which were typically 720x480 24FPS MPEG2. DVD drives were often shipped with accelerator cards that decoded MPEG2 in hardware. I had one. My netbook is many orders of magnitude faster than my old Pentium Pro. But it's not fast enough to decode 1080p 30fps H.265 or VP9 in software. It must decode VP9/H.265 on the GPU or not at all. MPEG2 is trivial to decode by comparison. I would expect a typical desktop PC of the mid '90s to take seconds to decode a frame of H.265, if it even had enough RAM to be able to do it at all. It's an engineering tradeoff between compression efficiency of the codec and the price of the hardware which is required to execute it. If a chip which is capable of decoding the old standard costs $8, and a chip which is capable of decoding the new standard costs $9, sure, the new standard will get lots of adoption. But if a chip which is capable of decoding the new standard costs $90, lots of vendors will balk.