I don't like newer codecs like AV1. I find them blurrier. Perhaps the bitrate is too low, but they do seem blurrier compared to h264. Even VP09 has often seemed better.

h264 is a very good codec.

they usually run newer codecs at a much lower bitrate, and do group testing to make sure the quality is "acceptable".

in double blind testing, at the same bitrate, you'll pick the "new" codec every time. but yes, they're trying to save money on bandwidth. it's annoying