>>106351521
Some 1080p videos are just cursed. They will fail to pass quality validation at anything below 20 Mbps even with modern video codecs. They look like videos to us humans but to video encoders all they see is random noise and they have a hard time compressing that.

So while AV1 will ON AVERAGE outperform H264 by 50% there will be freak edge cases like picrel.