For mobile, I don't know who outside of Netflix is delivering AV1. If they are, I expect them to be leveraging the hardware AV1 decoders for battery life instead of employing a software only solution like dav1d. Saying that, I think Netflix was using dav1d solution where it had a benefit (e.g. low quality cellular networks)

https://netflixtechblog.com/netflix-now-streaming-av1-on-and...

Pretty sure Youtube forces it with dav1d on devices that don’t support hw decoding which is how i became aware of the battery problem