IMO the biggest problem is that even for enterprise/large-scale-website scenarios, the combination of the product cost, the cost of downloading the decoder on e

IMO the biggest problem is that even for enterprise/large-scale-website scenarios, the combination of the product cost, the cost of downloading the decoder on each machine, and the increased cpu/gpu load (resulting in lower battery life) can drown out any advantage from the size reduction. The fact that it only works for a subset of video content is another problem. Switching to H265 or AV1 is way more compelling in practice because it works for everything, it's hardware accelerated, the decoders are off-the-shelf, and the quality is significantly improved. A modern GPU can both encode and decode H265.