I like encoding my videos in VP9 and Opus and it does work pretty well, except libvpx is very slow and inefficient. I have heard about Eve-AV1 and it seems to be pretty amazing, beating x265 by 10% + being faster than libvpx. Any chance to get a better VP9 encoder anytime soon?
AV1 is extremely slow to encode compared anything else including libvpx. There are multiple implementations, and we need to track and choose one that has been integrated into FFmpeg. Maybe sometime 2020.