JPEG, be it 8 bit or 12 bit or 16 bit has the guess that the camera firmware makes as to the colors, brightness, contrast, black levels, baked in, and difficult to change without introducing artifacts.
Raw is much more flexible in allowing those parameters to be adjusted before baking them in.
It will be a long time before most infra structure can use a new format. At first (5+ Yrs), most of the files will have to be down converted to 8 bit jpeg in order to use them anywhere. Eight bit jpeg is embedded into everything, and that's the issue. Printers, computer software, not just photo editing software or the web, but everything from e-mail to publication software to things like financial software, there is so much of it that some of it won't change for 50 years. Expensive multi million dollar custom software used by big corporations will not change quickly, some of that is 50 years old and uses long obsolete software like FAP, or more recently obsolete software like Cobol.