While the percentages look scary, it's only a slight difference (60kbps!) and still around 1mbps average, but with a significant quality boost (very crisp lines and near perfect quality). I bet Netflix could encode at nearly half that bitrate and stay similar to HEVC in quality, but I'm pleased they seem to have made a good tradeoff here.
It's actually quite amazing the quality that AV1 delivers at such low bitrates across the board. I've said it before, but AV1 is almost magical. Which I think is behind the lack of enthusiasm for VVC/h266; is anyone even using that? I've yet to actually see it in the wild.