I'll try to dig up the slide where they demonstrated it, but basically faster at equal quality than any software decoder of any codec.
Which is cool, but if you have hardware decode then you may not care, though software decode gets used in all sorts of weird places that you might not expect.
Yeah, the key is that newer generations of codecs use more time to encode, but often the decode time goes up less than the encode time. Combine that with greater design for parallelism and you find yourself in the slightly counterintuitive situation where decoding the same quality of video is faster in the newest codecs (at the one time cost of longer encodes).
I dont think it was one single slide I was thinking of but you can for example find comparisons of vp8, vp9, h264 by the same videolan/ffmpeg devs that demonstrate this general principle, the decode fps is surprisingly flat between software decodes of different codec families and generations.
The earlier generations often hit bottlenecks though, I think ffmpeg VP9 decode (built by the same people as dav1d) was the leader for a while but hits a wall at 4 cores due to format limitations. HEVC and especially dav1d have some gains when you can throw a modern amount of cores at it, and even phones often have 8.
Which is cool, but if you have hardware decode then you may not care, though software decode gets used in all sorts of weird places that you might not expect.