This paper is quite old and has known problems with setting a constant quantizer for VP9. The results do not match my own findings comparing libvpx and x265 at

This paper is quite old and has known problems with setting a constant quantizer for VP9. The results do not match my own findings comparing libvpx and x265 at all [1]. libvpx VP9 is still worse than x265, but the difference is quite small. [1] https://arewecompressedyet.com/ https://arewecompressedyet.com/