[Salgat]

Even without encoding, as long as decoding is supported for AV2, streaming sites like Youtube can always transcode uploads. The encoder on mobile hardware is more of a nice bonus as long as we have an AV1 encoder available in the meantime.

[Gigachad]

Youtube is doing this now. Most semi popular videos have an AV1 transcode, something interesting is I've seen youtube chooses to use the AV1 format even on my macbook which doesn't have a hardware decoder, I had a look at the CPU usage and there is a 50% load on one thread on my M1, but aside from extra battery usage, this is basically negligible since I'm likely not doing any other CPU heavy tasks while watching video.