Don't mean to discredit or invalidate your feelings, I just feel the need to disclaim that it's impossible to meet people's need with that granularity.
The alternative is that they keep XUL, make 0.1% of the install base happy, and ditch the performance increases that Quantum/WebExtension have given us... at which point there wouldn't be a NYT article and we'd all just be stuck in a browser monoculture.
I do not believe that was the only alternative. I have spent a lot of time reading bug reports / feature requests relating to this functionality, and it certainly seems that much of it could be enabled, but apparently never will. The developers seem to think that giving extensions "too much power" would be dangerous, and thus it is best not to let anybody choose power over safety guarantees.
It seems a little too harsh to bring up Linus Torvald's "If you think your users are idiots, only idiots will use it" quote, but it tends to come to my mind whenever I read the abovementioned discussions.