For reference: dav1d 0.5 can decode 143 FPS of a 1080p 8-bit video on a third gen core i7.[1] I doubt there's been much in the way of regressions since then. 10-bit and 4k is obviously a lot more heavy, but not really relevant to older devices.

[1] https://www.phoronix.com/news/dav1d-0.5 (it's mislabled as a core i3, but the 3770K is a core i7).