> There is a hell of a lot of manual work in running any sizeable network even within a single organisation.
I'm not trying to say they do everything, and no manual work is required. I'm trying to say machines are already doing part of it. OP believes that give a world where machines can code, they can't design or maintain networks, which I find truly ridiculous, since machines are pretty far from doing any kind of "coding" today, but they do networking and network protocols pretty well.
The first attempt at a system to turn plain English that even managers could write into executable code was 1959 - COBOL. So you're right in a sense, even 59 years later - but also wrong if you think networks are any more advanced than this. The Internet really cannot "reshape itself" and probably never will be able to.
Don't forget BGP. I don't think they do what you think they do, at least, not to the extent you think they do them. There is a hell of a lot of manual work in running any sizeable network even within a single organisation.