Another strong feature is the great upgrade path from existing jpeg files, which can be losslessly recompressed into jpeg xl with an additional ~20% compression

Another strong feature is the great upgrade path from existing jpeg files, which can be losslessly recompressed into jpeg xl with an additional ~20% compression. At this point I don't really see a reason for AVIF, hardware accelerated decoding could be a benefit, but AFAIK there's no device supporting it.