First, this is still the dawn of AV1 and the encoder you should be watching is SVT-AV1. You cannot conclude anything about the ultimate of AV1 encoding speed from experiences with a current version of ffmpeg.
As long as AV1 encoding (at useful compression etc) is within a small factor of HVEC, it will not be a factor in its success. License, quality, compression, and decoding speed are the things that matter.
As long as AV1 encoding (at useful compression etc) is within a small factor of HVEC, it will not be a factor in its success. License, quality, compression, and decoding speed are the things that matter.