Only NVIDIA 3000-series cards and up support hardware AV1 decoding and only 4000-series cards support both hardware AV1 encoding and decoding, so only just about 3 year old cards! source

All Intel ARC cards support both decode and encode, (released October 2022) source

AMD 6000-series cards (November 2020) support AV1 hardware decoding and only 7000-series cards (December 2022) support both hardware AV1 encoding and decoding. source