This is what turned me around: investigating and realizing that it is following the unix philosophy, it's just under the hood (under the other hood inside the bigger under the hood).
Most? I don't think that someone who installs Dash to Panel would say most of their features are extensions, just some essential ones. I feel like you could go as far as "If any essential features you use are gnome extensions you shouldn't be using gnome."
I do like the thing, "I'll never play this game" because they want to release a finished game-sized mod on volunteer work which never seems to pan out when you can't monetize due to it infringing on current copyright laws and of they do Microsoft will do something about it.
That's not what this is about, the author doesn't care about that, all they see is a finite, exploitable resource that will line their pockets.
However, to answer your question, we already have that technology.