Maybe you're just bad at reading text. Again, read the post carefully. Look around... nobody else had the same interpretation as you, so maybe that should clue you in something might be off with yours.
The post literally goes over known ways that JXL can be improved. The actual argument (and this is stated!) is whether those improvements will be enough to make JXL compelling to use for the web vs. other established formats (quality efficiency, encode/decode time, progressive loading, etc).
Also, don't assume AVIF or even WebP have maxxed out yet :) There are known ways to improve those two too!
The post literally goes over known ways that JXL can be improved. The actual argument (and this is stated!) is whether those improvements will be enough to make JXL compelling to use for the web vs. other established formats (quality efficiency, encode/decode time, progressive loading, etc).
Also, don't assume AVIF or even WebP have maxxed out yet :) There are known ways to improve those two too!