VP9 is the same generation as HEVC and performs about the same so the only reasons to favor one over the other would be financial and client support. For many providers this means 3 copies: VP9 for Android, HEVC for iOS/Mac, and H.264 for older devices.
AV1 is newer and should offer improvements over both previous generation codecs. Hardware support will be a significant factor but it’s looking as if in a few years you’ll have the option to use one better format on most modern devices.
AV1 is newer and should offer improvements over both previous generation codecs. Hardware support will be a significant factor but it’s looking as if in a few years you’ll have the option to use one better format on most modern devices.