Even on 1080p videos running on AV1 on 1x, the TV system bogs down and any kind of interaction has a variable 1-3s lag. On some TVs if you do 1.25x the TV automatically "downgrades" the resolution to 480p to avoid dropping frames.
I wish there was an option to still use VP9 / H.264 on those systems (even limited to 1080p).
What's missing mostly: live streams which are h264.
Currently, and I say currently, dav1d is so fast, no worries on that side.