They shifted to h.264 successfully, but I haven't heard of any more conferences to move forward in over a decade.
Currently "The Last of US S02E06" only has one AV1 - https://thepiratebay.org/search.php?q=The+Last+of+Us+S02E06 same THMT - https://thepiratebay.org/search.php?q=The+Handmaids+Tale+S06... These are low quality at only ~600MB, not really early adopter sizes.
AV1 beats h.265 but not h.266 - https://www.preprints.org/manuscript/202402.0869/v1 - People disagree with this paper on default settings
Things like getting hardware to The Scene for encoding might help, but I'm not sure of the bottleneck, it might be bureaucratic or educational or cultural.
[edit] "Common Side Effects S01E04" AV1 is the strongest torrent, that's cool - https://thepiratebay.org/search.php?q=Common+Side+Effects+S0...